Description and travel 133,845 Diseases 47,646 Data processing 45,190 Disabled veterans 37,638 Design and construction 31,201 Doctrines 31,095 Diplomatic relations 29,338 Dictionaries 29,154 Drama 23,926 Democracy 20,949 Directories 19,476 Design 18,509 Dialects 17,496 Death 17,117 Dissertations 16,175 Discovery and exploration 16,150 Diagnosis 14,958 Development 14,573 Decision making 14,340 Dogs 12,197 Drugs 11,115 Diseases and pests 10,280 Documentary films 10,256 Dwellings 9,871 Droit 9,294 Drug abuse 9,034 Debts, Public 8,320 Detective and mystery stories 8,202 Death and burial 8,041 Digital techniques 7,977 Database management 7,936 Dance 7,921 Destruction of property 7,425 Defenses 7,397 Drawing 6,844 Discourse analysis 6,019 Divorce 5,773 Defense contracts 5,523 Disaster relief 5,398 Dissertations, Academic 5,302 Decoration and ornament 5,293 Delivery of Health Care 5,159 Diaries 5,024 Dance music 4,873 Diet 4,633 Discrimination in employment 4,524 Drug traffic 4,456 Drug control 4,431 Differential equations 4,391 Data mining 4,377 Discoveries in geography 4,366 Desertion, Military and Naval 4,208 Discipline 4,148 Deaf 4,094 Dams 3,943 Decorative arts 3,760 Dentistry 3,743 Drug use 3,740 Dreams 3,696 Data protection 3,686 Democratization 3,473 Depressions 3,470 Diabetes 3,446 Differential equations, Partial 3,418 Databases 3,413 Discrimination & Race Relations 3,300 Distributed processing 3,280 Debtor and creditor 3,266 Dredging 3,198 Diplomatic history 3,113 Depression, Mental 3,110 Devotional literature 2,937 Demography 2,917 Developmental psychology 2,905 Dinosaurs 2,850 Domestic relations 2,850 Dynamics 2,840 Dissenters, Religious 2,804 Disarmament 2,764 Disabled Persons 2,761 Dating (Social customs) 2,741 Diplomats 2,728 Digital media 2,712 Domestic animals 2,706 Diet therapy 2,705 Drinking water 2,653 Demonology 2,647 Designs and plans 2,641 Disasters 2,598 Descriptions et voyages 2,490 DVDs 2,478 Doctrinal and controversial works 2,383 Discrimination 2,382 Decentralization in government 2,334 Dragons 2,334 Drug Therapy 2,333 Diagnostic Imaging 2,252 Dakota Indians 2,200 Debts, External 2,197 Drainage 2,195