Description and travel 135,602 Diseases 46,611 Data processing 44,335 Disabled veterans 37,594 Design and construction 30,986 Doctrines 30,793 Dictionaries 29,463 Diplomatic relations 28,393 Drama 23,376 Democracy 20,322 Directories 19,817 Design 18,012 Dialects 17,776 Death 16,689 Discovery and exploration 16,179 Dissertations 15,978 Diagnosis 14,500 Development 14,099 Decision making 13,879 Dogs 11,904 Drugs 10,919 Diseases and pests 10,287 Dwellings 9,782 Droit 9,165 Documentary films 9,114 Drug abuse 8,942 Debts, Public 8,325 Detective and mystery stories 8,016 Death and burial 7,976 Database management 7,835 Dance 7,808 Digital techniques 7,617 Destruction of property 7,425 Defenses 7,411 Drawing 6,743 Divorce 5,722 Discourse analysis 5,696 Defense contracts 5,494 Decoration and ornament 5,395 Dissertations, Academic 5,289 Disaster relief 5,220 Delivery of Health Care 5,052 Diaries 4,993 Dance music 4,835 Diet 4,516 Discrimination in employment 4,478 Differential equations 4,385 Discoveries in geography 4,365 Drug control 4,343 Drug traffic 4,337 Desertion, Military and Naval 4,208 Discipline 4,108 Data mining 4,102 Deaf 4,032 Dams 3,907 Decorative arts 3,790 Dentistry 3,756 Drug use 3,695 Dreams 3,634 Data protection 3,516 Depressions 3,435 Diabetes 3,421 Databases 3,412 Differential equations, Partial 3,401 Democratization 3,323 Distributed processing 3,249 Debtor and creditor 3,248 Dredging 3,188 Diplomatic history 3,105 Depression, Mental 3,066 Devotional literature 2,947 Discrimination & Race Relations 2,932 Demography 2,889 Dynamics 2,851 Domestic relations 2,836 Dissenters, Religious 2,817 Dinosaurs 2,814 Disarmament 2,775 Developmental psychology 2,767 Descriptions et voyages 2,733 Disabled Persons 2,704 Domestic animals 2,681 Diet therapy 2,675 Diplomats 2,674 Designs and plans 2,662 Drinking water 2,609 Dating (Social customs) 2,606 Demonology 2,568 Disasters 2,519 DVDs 2,503 Digital media 2,502 Doctrinal and controversial works 2,420 Drug Therapy 2,329 Decentralization in government 2,305 Discrimination 2,288 Dragons 2,242 Diagnostic Imaging 2,233 Drainage 2,204 Description 2,197 Dakota Indians 2,195