Book 1,317,190 Conference Proceeding 123,674 Electronic 60,037 Government Document 49,131 Thesis 38,149 Journal 35,229 Serial 27,275 Book Chapter 11,893 Unknown 10,434 Map 2,146 Manuscript 659 Audio 622 Reference Material 511 Kit 450 Photo 276 Physical Object 58 Musical Score 29 Article 26 Newspaper 19 see all ...

SpringerLink (Online service) 49,670 ebrary, Inc 13,991 ProQuest (Firm) 12,392 Geological Survey (U.S.) 8,515 United States National Bureau of Standards 8,176 De Gruyter 5,190 Edgar Fahs Smith Memorial Collection (University of Pennsylvania) 4,507 IEEE Xplore (Online service) 4,098 IEEE Computer Society 4,088 Society of Photo-optical Instrumentation Engineers 3,733 William B. Provine Collection on Evolution and Genetics 3,620 Institute of Electrical and Electronics Engineers 3,599 History of Science Collection (Brown University) 3,374 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 2,364 National Science Foundation (U.S.) 2,320 World Scientific (Firm) 2,213 EBSCOhost 1,890 United States National Aeronautics and Space Administration 1,752 Smithsonian Institution 1,735 North Atlantic Treaty Organization Scientific Affairs Division 1,710 NetLibrary, Inc 1,676 Edward Potts Cheyney Memorial Fund 1,650 Alumni and Friends Memorial Book Fund 1,548 ACM Digital Library 1,503 Cambridge University Press 1,439 Darwin, Charles, 1809-1882 1,391 Wiley InterScience (Online service) 1,365 Massachusetts Institute of Technology Center for Theoretical Physics 1,331 see all ...

English 1,120,866 German 103,865 French 79,750 Russian 46,073 Spanish 23,059 Latin 18,950 Italian 17,173 Chinese 16,174 Japanese 9,053 Portuguese 5,858 Dutch 5,608 Polish 4,211 Arabic 3,500 Swedish 3,428 Danish 2,287 Korean 2,242 Undetermined 2,076 Czech 2,022 Indonesian 1,880 Hebrew 1,510 Multiple 1,482 Ancient Greek 1,450 Romanian 1,440 Hungarian 1,299 Vietnamese 1,078 Turkish 1,067 Ukrainian 995 Norwegian 993 Greek 894 Persian 809 see all ...

Congresses 148,111 Electronic books 135,392 Conference papers and proceedings 106,193 Periodicals 47,983 History 30,868 Biography 22,194 Early works to 1800 21,600 Technical reports 16,054 Congress 14,388 Early works 13,877 Biographies 13,860 Classification 12,749 Dictionaries 11,961 Guidebooks 11,173 Identification 10,813 Pictorial works 10,547 Academic theses 9,096 Handbooks, manuals, etc 8,637 Textbooks 8,269 Juvenile literature 8,260 Laboratory manuals 7,955 Bibliography 7,620 Periodical 7,393 Electronic journals 7,349 Tables 6,999 Handbooks and manuals 6,782 Thèses et écrits académiques 6,719 Field guides 6,427 Congrès 6,423 Problems, exercises, etc 5,931 see all ...

Early works to 1800 5,952 20th century 4,292 19th century 3,969 Cretaceous 2,939 18th century 2,122 Quaternary 2,012 Tertiary 1,944 1900-1999 1,797 1809-1882 1,783 17th century 1,749 Devonian 1,670 Paleozoic 1,614 Pleistocene 1,584 1879-1955 1,455 Jurassic 1,333 1800-1899 1,311 Precambrian 1,244 From 65 to 140 million years ago 1,203 1564-1642 1,155 Carboniferous 1,144 Miocene 1,102 Ordovician 1,067 Cenozoic 1,057 Mesozoic 1,039 Permian 1,022 From 2 million years ago 1,013 Eocene 996 Silurian 945 1642-1727 940 Triassic 921 see all ...

United States 31,031 Germany 10,684 China 10,640 Great Britain 9,582 India 8,540 France 7,792 North America 7,740 Europe 6,233 Australia 6,150 California 6,104 Japan 5,899 England 5,759 Italy 5,505 Russia (Federation) 5,102 Soviet Union 4,908 Mexico 4,647 Canada 4,313 Brazil 3,776 Earth (Planet) 3,134 Alaska 3,131 New York (State) 3,118 Indonesia 2,857 Spain 2,839 Africa 2,739 Texas 2,518 South Africa 2,511 Sweden 2,501 Switzerland 2,393 Illinois 2,242 New Zealand 2,192 see all ...