Book 307,855 Government Document 242,360 Serial 27,439 Map 24,855 Reference Material 12,657 Conference Proceeding 11,121 Journal 9,147 Electronic 7,606 Unknown 6,804 Audio 1,047 Thesis 832 Photo 614 Musical Score 262 Kit 147 Newspaper 129 Manuscript 81 Book Chapter 23 Article 16 Physical Object 3 see all ...

H - Social Science 30,631 T - Technology 24,171 S - Agriculture 21,908 G - Geography, Anthropology, Recreation 13,967 R - Medicine 12,684 Q - Science 12,475 Z - Library Science 9,365 J - Political Science 8,985 A - General Works 7,528 D - World History 7,287 P - Language and Literature 6,317 N - Fine Arts 6,229 K - Law 4,972 E - United States History 3,533 L - Education 3,414 F - General American History 3,191 C - Historical Sciences 2,952 U - Military Science 1,834 B - Philosophy, Psychology, Religion 1,720 M - Music 1,213 V - Naval Science 571 see all ...

United States National Aeronautics and Space Administration 19,893 United States Forest Service 12,587 United States National Park Service 8,343 United States Soil Conservation Service 8,301 Langley Research Center 7,610 Library of Congress Congressional Research Service 6,286 U.S. Fish and Wildlife Service 5,981 United States Internal Revenue Service 5,240 United States Department of Agriculture. Economic Research Service 5,056 Lewis Research Center 3,562 United States Department of Energy 3,553 United States Agricultural Research Service 3,402 National Center for Health Statistics (U.S.) 2,832 United States Army Map Service 2,573 United States National Aeronautics and Space Administration. Scientific and Technical Information Branch 2,540 National Institutes of Health (U.S.) 2,248 Northeastern Forest Experiment Station (Radnor, Pa.) 2,139 United States National Aeronautics and Space Administration. Scientific and Technical Information Office 2,096 United States National Aeronautics and Space Administration Scientific and Technical Information Branch 2,095 Pacific Northwest Research Station (Portland, Or.) 2,058 Ames Research Center 2,044 United States National Ocean Service 2,017 National Institute for Occupational Safety and Health 1,973 Forest Products Laboratory (U.S.) 1,945 United States Department of Agriculture 1,799 United States National Archives and Records Service 1,768 Rocky Mountain Forest and Range Experiment Station (Fort Collins, Colo.) 1,700 United States Public Health Service 1,697 United States Joint Publications Research Service 1,642 North Central Forest Experiment Station (Saint Paul, Minn.) 1,569 see all ...

English 375,147 French 9,697 Russian 1,976 Spanish 1,765 German 977 Undetermined 823 Chinese 817 No linguistic content 358 Japanese 353 Italian 344 Hindi 323 Multiple 285 Arabic 270 Hebrew 266 Korean 249 Dutch 179 Portuguese 155 Indonesian 153 Polish 122 Latin 118 Yiddish 107 Bengali 84 Danish 77 Vietnamese 76 Afrikaans 73 Greek 67 Hungarian 64 Swedish 41 Tamil 41 Panjabi 40 see all ...

Maps 27,881 Periodicals 24,030 Statistics 18,867 Congresses 10,693 Bibliography 8,582 Conference papers and proceedings 6,775 Electronic books 5,736 Handbooks, manuals, etc 4,903 History 3,710 Documentary television programs 3,230 Directories 3,021 Catalogs 2,784 Internet videos 2,687 Drama 2,621 Bibliographies 2,568 Government publications 2,117 Handbooks and manuals 1,965 Abstracts 1,939 Internet resource 1,853 Topographic maps 1,760 Biography 1,257 Congress 1,222 Indexes 1,139 Statistics, Medical 1,124 Sources 1,105 Documentary films 1,026 Road maps 931 Forms 863 Nonfiction television programs 850 Rules and practice 826 see all ...

20th century 1,843 21st century 558 1945- 493 1900-1999 492 19th century 480 1939-1945 375 Civil War, 1861-1865 311 Since 1945 208 Revolution, 1775-1783 182 1900 - 1999 164 18th century 163 1800-1899 137 1809-1865 123 1960- 118 1933-1945 110 1945-1989 108 1989- 106 1946- 105 17th century 103 1991- 103 2000-2099 102 1858-1919 92 1918-1945 87 1949- 87 1961 - 1975 85 1861-1865 84 1914-1918 84 1976- 84 1985- 81 1564-1616 78 see all ...

United States 112,037 California 5,645 Australia 3,778 Alaska 3,670 Oregon 3,109 New York (State) 2,974 Washington (State) 2,717 France 2,640 Colorado 2,612 China 2,434 Texas 2,264 Florida 2,137 Arizona 2,086 Canada 2,057 New Mexico 1,979 North Carolina 1,976 Europe 1,909 India 1,908 Idaho 1,752 Pennsylvania 1,684 Montana 1,664 Mexico, Gulf of 1,661 Japan 1,626 Soviet Union 1,618 Michigan 1,522 Massachusetts 1,392 Virginia 1,392 Illinois 1,379 Southern States 1,377 Ohio 1,353 see all ...