Periodicals 18,655 Electronic books 13,788 Congresses 13,176 Conference papers and proceedings 9,808 History 7,817 Bibliography 4,535 Case studies 3,092 Directories 3,056 Handbooks, manuals, etc 2,207 Internet videos 2,166 Periodical 2,023 Biography 1,835 Bibliographies 1,783 Congress 1,751 Electronic journals 1,737 Statistics 1,660 Handbooks and manuals 1,435 Biographies 1,282 Abstracts 1,112 Educational films 868 Legislative hearings 829 Video recordings 710 Dictionaries 679 Directory 671 Criticism, interpretation, etc 656 Government publications 609 Périodiques 608 Interviews 591 Sources 584 Périodiques 579 Legislative materials 530 Aufsatzsammlung 507 Nonfiction television programs 481 Catalogs 480 Technical reports 480 Databases 459 Academic theses 447 Documentary films 429 Congrès 412 Cross-cultural studies 389 Legislative histories 387 Festschriften 375 Electronic book 370 Fiction 360 Indexes 360 periodicals 356 Observations 342 Congrès 328 Treaties 325 congresses 287 Computer network resources 281 Thèses et écrits académiques 269 Laboratory Manual 251 Laboratory manuals 249 Actes de congrès 245 Textbooks 245 Handbook 220 Laboratory Manuals 220 Radio news programs 215 Maps 212 Correspondence 200 Conference papers and proceedings 198 Exhibitions 193 Documentary television programs 192 Guides, manuels, etc 191 Essays 189 Oral histories (literary works) 182 Fulltext 181 Photographs 178 Nonfiction films 175 Longitudinal studies 171 Études de cas 169 Guides et manuels 168 Classification 165 Academic Dissertation 161 Autobiographies 161 Internet Resources 155 Lectures 155 Popular works 153 Feature films 145 Encyclopedias 140 Internet resource 139 Oral histories 138 dissertations 138 Serial publications 136 Early works to 1800 135 Exhibition catalogs 133 Pictorial works 132 Drama 126 Video recordings for the hearing impaired 126 CD-ROMs 118 doctoral dissertations 118 theses 118 masters theses 117 Kongress 115 Legislation 113 bibliography 113 Statistiques 110 Rules and practice 109 Bibliographie 107