Book 1,321,318 Conference Proceeding 123,848 Electronic 60,108 Government Document 49,183 Thesis 38,187 Journal 35,307 Serial 27,354 Book Chapter 11,968 Unknown 10,868 Map 2,148 Manuscript 661 Audio 625 Reference Material 513 Kit 450 Photo 281 Physical Object 58 Musical Score 29 Article 27 Newspaper 19 see all ...

SpringerLink (Online service) 49,835 ebrary, Inc 13,993 ProQuest (Firm) 12,363 Geological Survey (U.S.) 8,521 United States National Bureau of Standards 8,180 De Gruyter 5,205 Edgar Fahs Smith Memorial Collection (University of Pennsylvania) 4,509 IEEE Computer Society 4,101 IEEE Xplore (Online service) 4,099 Society of Photo-optical Instrumentation Engineers 3,731 Institute of Electrical and Electronics Engineers 3,648 William B. Provine Collection on Evolution and Genetics 3,623 History of Science Collection (Brown University) 3,378 National Institute of Standards and Technology (U.S.) 3,139 History of Medicine Collection (David M. Rubenstein Rare Book & Manuscript Library) 3,117 Association for Computing Machinery 2,367 National Science Foundation (U.S.) 2,345 World Scientific (Firm) 2,212 EBSCOhost 1,896 United States National Aeronautics and Space Administration 1,754 Smithsonian Institution 1,744 North Atlantic Treaty Organization Scientific Affairs Division 1,710 Edward Potts Cheyney Memorial Fund 1,650 Alumni and Friends Memorial Book Fund 1,549 ACM Digital Library 1,503 Cambridge University Press 1,438 Darwin, Charles, 1809-1882 1,393 Wiley InterScience (Online service) 1,382 NetLibrary, Inc 1,369 Massachusetts Institute of Technology Center for Theoretical Physics 1,331 see all ...

English 1,124,378 German 104,049 French 79,931 Russian 46,393 Spanish 23,265 Latin 19,003 Italian 17,234 Chinese 16,271 Japanese 9,102 Portuguese 5,875 Dutch 5,622 Polish 4,221 Arabic 3,519 Swedish 3,436 Danish 2,289 Korean 2,269 Undetermined 2,084 Czech 2,026 Indonesian 1,896 Hebrew 1,529 Multiple 1,487 Romanian 1,450 Ancient Greek 1,448 Hungarian 1,303 Vietnamese 1,089 Turkish 1,077 Ukrainian 1,001 Norwegian 995 Greek 901 Persian 814 see all ...

Congresses 148,312 Electronic books 134,724 Conference papers and proceedings 106,321 Periodicals 48,125 History 30,997 Biography 22,258 Early works to 1800 21,651 Technical reports 16,056 Congress 14,361 Biographies 13,971 Early works 13,952 Classification 12,798 Dictionaries 11,982 Guidebooks 11,189 Identification 10,854 Pictorial works 10,601 Academic theses 9,138 Handbooks, manuals, etc 8,677 Textbooks 8,329 Juvenile literature 8,301 Electronic journals 8,180 Laboratory manuals 7,962 Bibliography 7,619 Periodical 7,369 Tables 7,003 Handbooks and manuals 6,802 Field guides 6,495 Congrès 6,455 Problems, exercises, etc 5,967 Popular works 5,490 see all ...

Early works to 1800 5,953 20th century 4,330 19th century 3,993 Cretaceous 2,945 18th century 2,134 Quaternary 2,017 Tertiary 1,946 1900-1999 1,808 1809-1882 1,789 17th century 1,757 Devonian 1,676 Paleozoic 1,617 Pleistocene 1,586 1879-1955 1,465 Jurassic 1,339 1800-1899 1,315 Precambrian 1,244 From 65 to 140 million years ago 1,215 1564-1642 1,157 Carboniferous 1,151 Miocene 1,103 Ordovician 1,069 Cenozoic 1,061 Mesozoic 1,044 Permian 1,025 From 2 million years ago 1,022 Eocene 998 Silurian 949 1642-1727 940 Triassic 927 see all ...

United States 31,112 China 10,731 Germany 10,707 Great Britain 9,595 India 8,570 France 7,815 North America 7,764 Europe 6,246 Australia 6,164 California 6,112 Japan 5,928 England 5,776 Italy 5,532 Russia (Federation) 5,348 Soviet Union 4,916 Mexico 4,655 Canada 4,324 Brazil 3,783 Earth (Planet) 3,142 Alaska 3,136 New York (State) 3,124 Indonesia 2,879 Spain 2,849 Africa 2,744 Texas 2,525 South Africa 2,515 Sweden 2,503 Switzerland 2,403 Illinois 2,245 New Zealand 2,198 see all ...