Book 1,384,839 Conference Proceeding 127,930 Electronic 86,406 Government Document 49,266 Thesis 38,323 Journal 36,639 Serial 27,855 Book Chapter 12,075 Unknown 11,160 Map 2,189 Audio 718 Manuscript 663 Reference Material 519 Kit 455 Photo 360 Physical Object 59 Musical Score 29 Article 27 Newspaper 13 see all ...

SpringerLink (Online service) 47,239 ebrary, Inc 13,288 ProQuest (Firm) 12,369 Geological Survey (U.S.) 8,542 United States National Bureau of Standards 8,354 Institute of Electrical and Electronics Engineers 8,310 De Gruyter 5,199 IEEE Computer Society 4,768 Edgar Fahs Smith Memorial Collection (University of Pennsylvania) 4,504 Society of Photo-optical Instrumentation Engineers 4,462 IEEE Xplore (Online service) 4,108 William B. Provine Collection on Evolution and Genetics 3,623 History of Science Collection (Brown University) 3,376 History of Medicine Collection (David M. Rubenstein Rare Book & Manuscript Library) 3,157 National Institute of Standards and Technology (U.S.) 3,154 Association for Computing Machinery 2,383 National Science Foundation (U.S.) 2,350 World Scientific (Firm) 2,226 EBSCOhost 1,905 United States National Aeronautics and Space Administration 1,768 Smithsonian Institution 1,761 North Atlantic Treaty Organization Scientific Affairs Division 1,716 SPIE (Society) 1,682 Edward Potts Cheyney Memorial Fund 1,646 Alumni and Friends Memorial Book Fund 1,549 Cambridge University Press 1,531 ACM Digital Library 1,506 Darwin, Charles, 1809-1882 1,412 Wiley InterScience (Online service) 1,389 NetLibrary, Inc 1,381 see all ...

English 1,188,367 German 105,681 French 81,611 Russian 46,719 Spanish 23,730 Latin 19,111 Italian 17,392 Chinese 16,520 Japanese 9,317 Portuguese 5,973 Dutch 5,686 Polish 4,342 Arabic 3,545 Swedish 3,470 Korean 2,365 Danish 2,313 Undetermined 2,114 Czech 2,081 Indonesian 1,922 Hebrew 1,566 Multiple 1,499 Romanian 1,459 Ancient Greek 1,458 Hungarian 1,305 Vietnamese 1,100 Turkish 1,096 Ukrainian 1,035 Norwegian 1,005 Greek 905 Persian 827 see all ...

Congresses 160,043 Electronic books 126,978 Conference papers and proceedings 106,693 Periodicals 49,770 History 31,315 Biography 22,719 Early works to 1800 21,778 Technical reports 16,065 Congress 14,422 Biographies 14,175 Early works 14,095 Classification 12,974 Dictionaries 12,080 Guidebooks 11,246 Identification 11,109 Pictorial works 10,782 Academic theses 9,199 Juvenile literature 9,145 Handbooks, manuals, etc 9,023 Textbooks 8,559 Laboratory manuals 8,008 Bibliography 7,656 Periodical 7,553 Tables 7,067 Handbooks and manuals 6,855 Field guides 6,634 Congrès 6,481 Problems, exercises, etc 6,168 Popular works 5,673 Electronic journals 5,479 see all ...

Early works to 1800 5,942 20th century 4,497 19th century 4,134 Cretaceous 2,971 18th century 2,192 Quaternary 2,049 Tertiary 1,955 1809-1882 1,845 1900-1999 1,832 17th century 1,820 Devonian 1,681 Paleozoic 1,623 Pleistocene 1,595 1879-1955 1,517 Jurassic 1,347 1800-1899 1,341 Precambrian 1,252 From 65 to 140 million years ago 1,245 1564-1642 1,179 Carboniferous 1,166 Miocene 1,110 Ordovician 1,074 Cenozoic 1,068 Mesozoic 1,054 From 2 million years ago 1,040 Permian 1,034 Eocene 1,002 1642-1727 967 Silurian 957 Triassic 937 see all ...

United States 32,139 China 10,892 Germany 10,816 Great Britain 9,811 India 8,680 France 7,948 North America 7,886 Europe 6,382 Australia 6,331 California 6,179 Japan 6,038 England 5,856 Italy 5,593 Russia (Federation) 5,405 Soviet Union 4,958 Mexico 4,737 Canada 4,388 Brazil 3,843 Earth (Planet) 3,203 Alaska 3,178 New York (State) 3,154 Indonesia 2,923 Spain 2,894 Africa 2,796 Texas 2,558 South Africa 2,543 Sweden 2,526 Switzerland 2,443 Illinois 2,263 New Zealand 2,215 see all ...