Terms: NSF Digital Library (8,360), national science digital library (649,000),
Terms: scientific journal (4,110,000), scientific journals (5,890,000), journals websites (114,000), libraries (458,000,000), library (2,020,000,000), library catalogs (3,540,000), digital library (35,700,000), digital libraries (6,070,000),
Boolean: intitle:library (95,000,000), inurl:library (131,000,000), intitle:"library catalog" (646,000),
Boolean: site:loc.gov (1,460,000), site:catalog.loc.gov (7), site:americaslibrary.gov (5,470), site:memory.loc.gov (1,210,000), site:cip.loc.gov (52), site:copyright.gov (13,300), site:pcn.loc.gov (24), site:international.loc.gov (1,700), site:digitalpreservation.gov (907), site:glin.gov (49,300), site:usa.gov (6,290),
Boolean: site:/international.loc.gov +inurl:/intldl (660), site:/memory.loc.gov +inurl:/ammem (35,800), site:/memory.loc.gov +inurl:/learn (6,290), site:/americaslibrary.gov +inurl:/cgi-bin (0), site:/copyright.gov +inurl:/carp (153), site:/copyright.gov +inurl:/forms (96), site:/copyright.gov +inurl:/laws (2), site:/copyright.gov +inurl:/newsnet (368), site:/copyright.gov +inurl:/records (16), site:/copyright.gov +inurl:/register (83), site:/loc.gov +inurl:/about (1,470), site:/loc.gov +inurl:/access (48), site:/loc.gov +inurl:/acq (2,990), site:/loc.gov +inurl:/bookfest (1,430), site:/loc.gov +inurl:/catdir (31,700), site:/loc.gov +inurl:/cds (1,770), site:/loc.gov +inurl:/exhibits (3,630), site:/loc.gov +inurl:/families (2), site:/loc.gov +inurl:/flicc (1,740), site:/loc.gov +inurl:/folklife (1,710), site:/loc.gov +inurl:/help (1,050), site:/loc.gov +inurl:/homepage (21), site:/loc.gov +inurl:/hr (136), site:/loc.gov +inurl:/ils (317), site:/loc.gov +inurl:/issn (85), site:/loc.gov +inurl:/jefftour (39), site:/loc.gov +inurl:/law (2,250), site:/loc.gov +inurl:/library (706), site:/loc.gov +inurl:/loc (1,460,000), site:/loc.gov +inurl:/marc (3,100), site:/loc.gov +inurl:/minerva (694), site:/loc.gov +inurl:/more (113), site:/loc.gov +inurl:/nls (2,360), site:/loc.gov +inurl:/philanthropy (24), site:/loc.gov +inurl:/poetry (624), site:/loc.gov +inurl:/preserv (663), site:/loc.gov +inurl:/pressroom (10), site:/loc.gov +inurl:/rr (28,200), site:/loc.gov +inurl:/search (5,920), site:/loc.gov +inurl:/shop (4,780), site:/loc.gov +inurl:/standards (1,790), site:/loc.gov +inurl:/teachers (1,080), site:/loc.gov +inurl:/today (7,030), site:/loc.gov +inurl:/wiseguide (720),
Directory of open access journals
Boolean: site:nsdl.org (88,000), site:ansp.org (10,900), site:portal.acm.org (36,700), site:engineeringpathway.com (0), site:alsos.wlu.edu (6,380), site:ams.org (167,000), site:amnh.org (93,500), site:amser.org (5,160), site:asdlib.org (1,170), site:animaldiversity.ummz.umich.edu (7,460), site:education.arm.gov (954), site:atomicarchive.com (1,820), site:pests.ifas.ufl.edu (1), site:beyondpenguins.nsdl.org (363), site:nsdl.org (88,000), site:biomedcentral.com (552,000), site:bioone.org (390), site:biosciednet.org (9,470), site:blackwell-synergy.com (1,100), site:www2.vims.edu (358), site:vims.edu (10,300), site:caltechcstr.library.caltech.edu (805), site:caltecheerl.library.caltech.edu (891), site:etd.caltech.edu (7,000), site:journals.cambridge.org (2,290), site:cambridge.org (894,000), site:cosee.net (389), site:chemcases.com (500), site:chemeddl.org (1,740), site:indiana.edu (804,000), site:dlese.org (30,700), site:meted.ucar.edu (3,360), site:compadre.org (19,500), site:math.duke.edu (31,100), site:causeweb.org (2,190), site:shodor.org (24,900), site:learningobjects.wesleyan.edu (1,020), site:mathdemos.gcsu.edu (1,730), site:dlnet.vt.edu (305), site:dlisr.org (23), site:dlist.sir.arizona.edu (6,180), site:csmate.colostate.edu (1,650), site:doaj.org (235,000), site:dspace.mit.edu (50,800), site:eprints.rclis.org (34), site:serc.carleton.edu (16,700), site:sceccore.usc.edu (1), site:econport.org (973), site:eduplace.com (49,800), site:strandmaps.nsdl.org (61), site:piru.alexandria.ucsb.edu (51), site:eerl.org (1,720), site:elsevier.com (296,000), site:epa.gov (529,000), site:esa21.kennesaw.edu (297), site:cwis.fcla.edu (2), site:nsdl.exploratorium.edu (872), site:explorelearning.com (4,540), site:classzone.com (15,200), site:palmm.fcla.edu (12), site:thefunworks.org (1), site:eecgsdl.edc.org (1,090), site:grow.arizona.edu (8,020), site:archive.globe.gov (165), site:hsdvl.org (450), site:healcentral.org (5,360), site:hiroshima-remembered.com (154), site:images.library.uiuc.edu (18,500), site:ilumina-dlib.org (1,710), site:infomine.ucr.edu (47), site:ia.usu.edu (2,160), site:rgeoghegan.1free.ws (0), site:scout.wisc.edu (118,000), site:vts.intute.ac.uk (17,700), site:auburn.edu (316,000), site:mathdl.maa.org (7,850), site:birds.cornell.edu (16,700), site:matdl.org (2,260), site:mathforum.org (695,000), site:mathdl.org (139), site:mathsurvey.org (5), site:mel.org (8,160), site:msteacher.org (4,800), site:monarchwatch.org (33,000), site:mynasadata.larc.nasa.gov (870), site:nap.edu (786), site:curvebank.calstatela.edu (386), site:nsf.gov (71,500), site:learningcenter.nsta.org (5,420), site:stevekluge.com (420), site:nnvl.noaa.gov (11,000), site:wiki.nsdl.org (2), site:expertvoices.nsdl.org (7,540), site:whiteboard.comm.nsdl.org (1), site:opl.apa.org (210), site:osti.gov (188,000), site:priweb.org (1,400), site:planetmath.org (17,500), site:prisms.mmsa.org (292), site:projecteuclid.org (75,600), site:plos.org (2,620), site:pubmedcentral.nih.gov (1,260,000), site:rpids.csc.tntech.edu (10), site:reciprocalnet.org (7,950), site:sciam.com (46,600), site:svs.gsfc.nasa.gov (43,400), site:simplescience.org (105), site:springer.com (297,000), site:taylorandfrancisgroup.com (30), site:teachengineering.com (1,420), site:teachersdomain.org (6,740), site:teach12.com (2,110), site:tomsnyder.com (1,710), site:toolfactory.com (3,040), site:trinityremembered.com (100), site:tao.truststc.org (8), site:digital.library.wisc.edu (2,890), site:physicsdemos.com (65), site:dlib.vt.edu (7,830), site:math.uah.edu (1,550), site:visionlearning.com (4,310), site:lcweb2.loc.gov (113,000), site:caltechkhr.library.caltech.edu (94), site:functions.wolfram.com (55,300), site:mathworld.wolfram.com (5,790),
Terms: Changes in the Earth's Surface (24,500), earthquakes and volcanoes (427,000), rates of change (1,120,000), weathering and erosion (185,000), rocks and sediments (40,400), Plate Tectonics (3,610,000), the earth's interior (559,000), evidence of plates (206), earthquakes and volcanoes (427,000), Solar System (55,300,000), relative motion (1,150,000), phases of the moon (1,780,000), observations of the sky (17,800), the planets (16,000,000), telescopes (50,600,000), Stars (1,950,000,000), the sun and stars (361,000), observations of the sky (17,800), telescopes (50,600,000), Galaxies and the Universe (79,500), telescopes (50,600,000), light (2,390,000,000), galaxies (47,000,000), Gravity (159,000,000), relative motion (1,150,000), observations of the sky (17,800), the earth's gravity (414,000), forces and motion (247,000), Atoms and Molecules (1,680,000), invisibly tiny pieces (33), basic ingredients (2,140,000), Conservation of Matter (163,000), changes of state (164,000), changing vs. constant properties (28), parts and wholes (63,400), keeping track (18,600,000), States of Matter (1,110,000), emergent properties (643,000), heat energy (2,800,000), changes of state (164,000), Chemical Reactions (7,700,000), basic ingredients (2,140,000), changing properties (189,000), reaction rates (935,000), Evidence and Reasoning in Inquiry (96), lines of reasoning (153,000), observations and evidence (15,600), Scientific Investigations (2,050,000), control and conditions (1,970), reliability of results (72,300), record-keeping (67,000,000), kinds of investigations (43,000), Scientific Theories (2,520,000), making sense of evidence (25,600), alternative explanations (1,320,000), theory modification (1,240), Avoiding Bias in Science (67), reliability of results (72,300), safeguards (38,500,000), expectations and explanations (829), The Scientific Community (10,700,000), disciplines (140,000,000), employment and funding (16,300), people (8,440,000,000), scientific communication (896,000), Science and Society (3,510,000), ethics in research (193,000), society affects science (68), science affects society (676), Mathematical Processes (188,000), studying patterns (42,900), representation and abstraction (45,300), computation and operations (1,320), Mathematical Models (5,730,000), representation and modeling (14,600), correspondence (147,000,000), choices in mathematics (344), interpreting results (546,000), Nature of Mathematics (165,000), universal language for describing things (24), connections to science and technology (502), study of patterns (90,500), Design Constraints (695,000), trade-offs in design (1,840), physical constraints (856,000), social constraints (426,000), Designed Systems (449,000), feedback and control (91,100), interacting parts (71,300), failure (552,000,000), Laws of Motion (1,640,000), relative motion (1,150,000), forces and motion (247,000), Waves (235,000,000), light (2,390,000,000), wave motion (1,100,000), vibrations (39,300,000), DNA and Inherited Characteristics (77), mechanism of inheritance (29,900), sexual reproduction (1,790,000), cells and development (61,600), Variation in Inherited Characteristics (714), variation (165,000,000), sexual reproduction (1,790,000), mechanism of inheritance (29,900), Biological Evolution (1,650,000), evidence from existing organisms (34), fossil evidence (1,100,000), Natural selection (17,700,000), changing environments (1,080,000), variation and advantage (47), inherited characteristics (129,000), artificial selection (489,000), Materials Science (22,400,000), physical properties (12,500,000), synthesis and use of materials (37), resource depletion and recycling (34), Agricultural Technology (1,540,000), controlling characteristics (2,250), producing food (825,000), transporting food (225,000), effects on society (432,000), Communication Technology (17,800,000), devices and media (207,000), coding and decoding (167,000), quality of communication (338,000), Computers (1,850,000,000), digital coding (89,200), storing and processing information (14,800), calculating and modeling (459), Graphic Representation (1,460,000), locating points (44,400), graphic displays (7,260,000), related changes (221,000,000), alternative representations (153,000), Symbolic Representation (916,000), alternative representations (153,000), symbols and equations (49,900), working with equations (13,600), Ratios and Proportionality (303), parts and wholes (63,400), description and comparison (57,000), computation (51,000,000), Describing Change (20,000), related changes (221,000,000), kinds of change (143,000), invariance (3,370,000), Interaction of Technology and Society (1,010), valuing technology (17,800), society influences technology (162), technology affects society (3,600), Decisions about Using Technology (344), trade-offs (9,190,000), costs and benefits (9,170,000), risks and side-effects (368,000), valuing technology (17,800), Flow of Energy in Ecosystems (1,630), energy in living things (1,350), plants making food (434), food web (3,240,000), Flow of Matter in Ecosystems (132), plants making food (434), food web (3,240,000), matter cycles (17,800), Cell Functions (839,000), basic needs (12,800,000), basic functions (4,710,000), structures (369,000,000), Cells and Organs (196,000), cell differentiation (3,570,000), structure (852,000,000), division of labor (4,180,000), functions of organs (18,200), Disease (698,000,000), genetic problems (565,000), the body's defenses (274,000), infection (207,000,000), Maintaining Good Health (673,000), diet and exercise (10,700,000), harmful substances (2,350,000), conditions for health (50,000), Coping With Mental Distress (352), mind/body (53,800,000), different responses (1,580,000), different standards (2,980,000), Diagnosis and Treatment of Mental Disorders (33,700), mind/body (53,800,000), getting help (16,500,000), self-awareness (11,300,000), Influences on Social Change (222), rules and government (34,000), internal influences on change (29), external influences on change (30), Social Decisions (116,000), consequences of decisions (171,000), costs, benefits, and alternatives (1,090), personal interests (10,900,000), rules and government (34,000), Heredity and Experience Shape Behavior (45), learning from others (884,000), beliefs and biases (27,800), learning from experience (846,000), effects of heredity (11,700), Culture Affects Behavior (477), groups and subcultures (13,000), cultural influences (2,580,000), learning from others (884,000), reward and punishment (565,000), Averages and Comparisons (556), control and conditions (1,970), comparing groups (85,200), averages and spreads (331), Correlation (81,400,000), control and conditions (1,970), related changes (221,000,000), Statistical Reasoning (229,000), probability (116,000,000), prediction (123,000,000), sampling (135,000,000), Systems (2,480,000,000), boundaries (166,000,000), interacting parts (71,300), emergent properties (643,000), complexity (155,000,000), Manufacturing (834,000,000), materials (1,390,000,000), manipulation skills (142,000), manufacturing (834,000,000), societal implications (463,000), Health Technology (7,460,000), diagnosis (219,000,000), treatment (995,000,000), prevention (479,000,000), Scientific World View (150,000), limits of science (214,000), investigating a knowable world (27), continuity and change (1,450,000), Technology and Science (4,050,000), effect of technology on science (36), effect of science on technology (31), effect on society (440,000), Weather and Climate (4,530,000), temperature and winds (32,900), water cycle (3,660,000), atmosphere (472,000,000), climate change (263,000,000), Use of Earth's Resources (3,600), use of energy resources (89,100), needs of organisms for Earth's resources (30), human impact on the environment (152,000), use of material resources (17,500), Energy Transformations (174,000), forms of energy (2,820,000), conservation (349,000,000), dissipation (15,200,000), Electricity and Magnetism (1,700,000), effects at the atomic level (184), electric charge (2,100,000), electric currents (933,000), electromagnetism (3,510,000), Diversity of Life (1,760,000), classification (230,000,000), similarities and differences (6,570,000), diversity and survival (1,430), Interdependence of Life (57,800), interactions among organisms (27,700), dynamic nature of ecosystems (1,880), dependence of organisms on their environment (28), human impact (2,760,000), Human Identity (705,000), similarity to other species (620), physical attributes of the human species (25), behavioral attributes of the human species (25), use of technology (12,300,000), Human Development (30,900,000), risks and survival (650), growth and development (22,000,000), cell differentiation (3,570,000), fertilization and contraception (103), Basic Functions (4,710,000), deriving energy from food (553), defense (780,000,000), coordination (172,000,000), reproduction (470,000,000), Group Behavior (897,000), group identity (1,480,000), group action (1,590,000), Political and Economic Systems (443,000), politics (2,320,000,000), economics (479,000,000), Social Conflict (1,400,000), reasons for conflict (32,100), resolving conflict (1,530,000), Global Interdependence (492,000), communication and transportation technologies (5,920), trade (2,120,000,000), treatise (18,400,000), Energy Resources (23,200,000), resources (4,340,000,000), efficient use (12,800,000), societal and environmental implications (1,770), Numbers (1,590,000,000), number operations (257,000), describing quantities (1,070), Shapes (178,000,000), shapes in the real world (1,470), properties of shapes and their relationships (35), Reasoning (91,700,000), use of deductive logic in reasoning (27), use of evidence in reasoning (36), use of inductive logic in reasoning (25), use of analogies in reasoning (30), The Copernican Revolution (136,000), determining the structure of the solar system (25), nature of science (1,830,000), Classical Mechanics (1,820,000), historical development and influence (300), nature of science (1,830,000), Relativity (28,300,000), mass and energy equivalence (230), theory development by Einstein (26), nature of science (1,830,000), The Chemical Revolution (28,200), scientific understanding (2,980,000), history of development (1,380,000), nature of science (1,830,000), Moving the Continents (1,030), scientific ideas about plate tectonics (26), development of scientific understanding of the motion of continents (25), determining the age of the earth (1,690), nature of science (1,830,000), Splitting the Atom (118,000), scientific understanding (2,980,000), history of development (1,380,000), nature of science (1,830,000), Explaining Evolution (33,500), scientific ideas about evolution (192), development and acceptance of scientific ideas about evolution (24), determining the age of the earth (1,690), nature of science (1,830,000), Discovering Germs (854), development of germ theory (586), nature of science (1,830,000), The Industrial Revolution (8,630,000), technological understanding (75,200), nature of technology (403,000), history of development (1,380,000), Models (1,130,000,000), uses of models (12,400), limitations of models (32,200), Constancy (4,880,000), conservation (349,000,000), equilibrium (50,100,000), Patterns of Change (560,000), directional change (136,000), predicting change (33,800), cyclic change (29,000), monitoring change (159,000), Scale (739,000,000), effect of size on properties (26), variety of magnitudes in nature (25), describing extremes (530), Values in Science (35,600), values particular to science (24), common values as applied in science (25), Public Perception of Science (34,700), ethics in research (193,000), value and limits of science (41), value and limits of technology (30), Computation and Estimation (74,500), estimation (79,900,000), computation (51,000,000), Using Tools and Devices (344), making accurate measurements (24,300), working with tools and troubleshooting devices (24), recording and organizing information (1,180), Communication Skills (53,700,000), mathematical communication (75,100), visual communication (7,380,000), oral and written communication (2,900,000), Detecting Flaws in Arguments (47), detecting bias (31,400), detecting misuse of numbers (26), detecting overgeneralization (29), detecting unfair comparisons (0), detecting flawed reasoning (26), detecting alternative explanations (25), detecting unsupported claims (24),