Book 6,799 Government Document 860 Serial 410 Journal 309 Conference Proceeding 82 Book Chapter 73 Electronic 47 Thesis 24 Reference Material 20 Article 3 Unknown 3 Kit 1 Manuscript 1 see all ...

United States National Bureau of Standards 170 Geological Survey (U.S.) 138 Edgar Fahs Smith Memorial Collection (University of Pennsylvania) 67 Smithsonian Institution 61 Library of Congress Science and Technology Division. Reference Section 49 History of Science Collection (Brown University) 37 National Institute of Standards and Technology (U.S.) 32 William B. Provine Collection on Evolution and Genetics 30 U.S. Atomic Energy Commission 28 History of Medicine Collection (David M. Rubenstein Rare Book & Manuscript Library) 26 National Agricultural Library (U.S.) 25 Westley, Francis 22 Williams, Jean Balch 22 Bolton, Henry Carrington, 1843-1903 20 National Research Council (U.S.) Research Information Service 20 Akademii︠a︡ nauk SSSR Biblioteka 19 Fuhr, J. R 19 West, Clarence J (Clarence Jay), 1886-1953 19 Wiese, W. L 19 Lutz, G. J (George John), 1933- 18 United States Bureau of Standards 18 United States National Museum 18 Geological Society of America 16 Gezari, Daniel Y 16 National Library of Medicine (U.S.) 16 United States Department of Commerce 16 United States National Bureau of Standards. Office of Standard Reference Data 16 Akademii͡a nauk SSSR Biblioteka 15 American Association for the Advancement of Science 15 American Chemical Society Division of Chemical Literature 15 see all ...

English 5,741 German 612 French 489 Russian 365 Spanish 178 Italian 130 Latin 85 Portuguese 54 Japanese 49 Chinese 45 Swedish 32 Dutch 30 Polish 28 Arabic 24 Multiple 23 Czech 22 Ukrainian 22 Romanian 19 Danish 16 Undetermined 13 Lithuanian 12 Turkish 11 Croatian 9 Hungarian 8 Georgian 7 Korean 7 Latvian 7 Bulgarian 6 Persian 6 Finnish 5 see all ...

18th century 30 19th century 29 Early works to 1800 28 1707-1778 27 1809-1882 23 17th century 20 Paleozoic 18 20th century 16 1800-1899 14 1564-1642 13 1879-1955 13 1707-1783 11 1733-1804 11 From 230 to 570 million years ago 11 Quaternary 11 16th century 10 1783-1840 10 From 2 million years ago 10 Tertiary 10 1700-1799 9 1845-1923 9 Cretaceous 9 1473-1543 7 Carboniferous 7 1514-1564 6 1550-1617 6 1571-1630 6 1600-1699 6 1700-1899 6 1863-1945 6 see all ...

United States 333 North America 140 Soviet Union 114 Great Britain 77 Germany 74 Canada 68 Italy 61 Japan 61 Russia (Federation) 57 China 55 France 51 England 50 India 48 Brazil 43 Mexico 37 Australia 36 Europe 33 Spain 33 Russia 32 Alaska 29 California 28 Poland 26 South America 26 New York (State) 24 Ukraine 23 Pennsylvania 22 New Zealand 21 Middle East 19 Ohio 19 Illinois 17 see all ...