Book 1,383,692 Conference Proceeding 127,898 Electronic 86,363 Government Document 49,264 Thesis 38,302 Journal 36,635 Serial 27,855 Book Chapter 12,046 Unknown 11,561 Map 2,149 Audio 718 Manuscript 663 Reference Material 522 Kit 454 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) 12,368 Geological Survey (U.S.) 8,538 United States National Bureau of Standards 8,324 Institute of Electrical and Electronics Engineers 8,309 De Gruyter 5,202 IEEE Computer Society 4,768 Edgar Fahs Smith Memorial Collection (University of Pennsylvania) 4,507 Society of Photo-optical Instrumentation Engineers 4,471 IEEE Xplore (Online service) 4,108 William B. Provine Collection on Evolution and Genetics 3,624 History of Science Collection (Brown University) 3,377 History of Medicine Collection (David M. Rubenstein Rare Book & Manuscript Library) 3,159 National Institute of Standards and Technology (U.S.) 3,159 Association for Computing Machinery 2,384 National Science Foundation (U.S.) 2,353 World Scientific (Firm) 2,226 EBSCOhost 1,898 United States National Aeronautics and Space Administration 1,767 Smithsonian Institution 1,759 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 1,410 Wiley InterScience (Online service) 1,388 NetLibrary, Inc 1,381 see all ...

English 1,187,923 German 105,564 French 81,538 Russian 46,706 Spanish 23,663 Latin 19,104 Italian 17,362 Chinese 16,489 Japanese 9,300 Portuguese 5,959 Dutch 5,678 Polish 4,337 Arabic 3,537 Swedish 3,465 Korean 2,357 Danish 2,312 Undetermined 2,113 Czech 2,078 Indonesian 1,915 Hebrew 1,561 Multiple 1,497 Romanian 1,459 Ancient Greek 1,456 Hungarian 1,305 Vietnamese 1,101 Turkish 1,089 Ukrainian 1,034 Norwegian 1,005 Greek 902 Persian 822 see all ...

Congresses 160,000 Electronic books 127,590 Conference papers and proceedings 106,612 Periodicals 49,770 History 31,227 Biography 22,672 Early works to 1800 21,779 Technical reports 16,067 Congress 14,417 Biographies 14,095 Early works 14,068 Classification 12,953 Dictionaries 12,074 Guidebooks 11,239 Identification 11,092 Pictorial works 10,759 Academic theses 9,168 Juvenile literature 9,119 Handbooks, manuals, etc 9,020 Textbooks 8,547 Laboratory manuals 7,994 Bibliography 7,652 Periodical 7,550 Tables 7,060 Handbooks and manuals 6,830 Field guides 6,582 Congrès 6,466 Problems, exercises, etc 6,180 Popular works 5,655 Electronic journals 5,480 see all ...

Early works to 1800 5,957 20th century 4,489 19th century 4,121 Cretaceous 2,968 18th century 2,183 Quaternary 2,047 Tertiary 1,953 1809-1882 1,842 1900-1999 1,827 17th century 1,813 Devonian 1,680 Paleozoic 1,623 Pleistocene 1,595 1879-1955 1,519 Jurassic 1,347 1800-1899 1,331 Precambrian 1,250 From 65 to 140 million years ago 1,236 1564-1642 1,178 Carboniferous 1,165 Miocene 1,109 Ordovician 1,071 Cenozoic 1,067 Mesozoic 1,052 From 2 million years ago 1,032 Permian 1,030 Eocene 1,002 1642-1727 964 Silurian 957 Triassic 936 see all ...

United States 32,117 China 10,869 Germany 10,804 Great Britain 9,787 India 8,645 France 7,942 North America 7,882 Europe 6,370 Australia 6,320 California 6,177 Japan 6,025 England 5,851 Italy 5,580 Russia (Federation) 5,403 Soviet Union 4,955 Mexico 4,723 Canada 4,381 Brazil 3,835 Earth (Planet) 3,202 Alaska 3,166 New York (State) 3,155 Indonesia 2,913 Spain 2,891 Africa 2,795 Texas 2,556 South Africa 2,540 Sweden 2,523 Switzerland 2,439 Illinois 2,263 New Zealand 2,215 see all ...