Periodicals 18,643 Electronic books 14,078 Congresses 13,165 Conference papers and proceedings 9,806 History 7,810 Bibliography 4,520 Case studies 3,087 Directories 3,057 Handbooks, manuals, etc 2,199 Internet videos 2,165 Periodical 2,028 Biography 1,832 Bibliographies 1,781 Congress 1,754 Electronic journals 1,738 Statistics 1,658 Handbooks and manuals 1,434 Biographies 1,276 Abstracts 1,112 Educational films 867 Legislative hearings 829 Video recordings 709 Dictionaries 677 Directory 671 Criticism, interpretation, etc 656 Périodiques 639 Government publications 613 Interviews 591 Sources 582 Périodiques 558 Legislative materials 529 Aufsatzsammlung 510 Nonfiction television programs 481 Catalogs 480 Technical reports 480 Databases 459 Academic theses 447 Documentary films 428 Congrès 406 Cross-cultural studies 390 Legislative histories 387 Electronic book 372 Festschriften 370 Indexes 360 Fiction 358 periodicals 347 Observations 342 Congrès 325 Treaties 325 congresses 287 Computer network resources 281 Thèses et écrits académiques 269 Laboratory Manual 252 Laboratory manuals 250 Actes de congrès 248 Textbooks 246 Handbook 221 Laboratory Manuals 220 Radio news programs 215 Maps 212 Conference papers and proceedings 198 Correspondence 197 Exhibitions 193 Documentary television programs 191 Guides, manuels, etc 189 Essays 188 Oral histories (literary works) 182 Fulltext 181 Photographs 177 Guides et manuels 175 Nonfiction films 174 Études de cas 171 Longitudinal studies 171 Classification 165 Autobiographies 163 Academic Dissertation 162 Internet Resources 155 Lectures 154 Popular works 152 Feature films 141 Encyclopedias 140 Internet resource 139 Oral histories 138 dissertations 138 Early works to 1800 136 Serial publications 136 Exhibition catalogs 133 Pictorial works 131 Drama 124 Video recordings for the hearing impaired 124 CD-ROMs 118 doctoral dissertations 118 theses 118 masters theses 117 Kongress 113 Legislation 113 Statistiques 113 bibliography 113 handbooks 112 Rules and practice 109