Politics and government 1,576,050 Philosophy 317,281 Political science 290,149 Periodicals 284,900 Political aspects 120,342 Popular music 119,921 Piano music 107,455 Prevention 96,429 Population 88,452 Psychological aspects 88,303 Poetry 84,622 Psychology 84,290 Political activity 75,951 Presidents 68,345 PRO Gotham Book Mart (former owner) (Gotham Book Mart Collection copy) 59,533 Photography, Artistic 57,698 Pollution 53,384 Pictorial works 50,404 Politique et gouvernement 50,180 Public opinion 49,995 Public health 49,502 POLITICAL SCIENCE 48,826 Planning 48,747 Painting 47,330 Physics 46,856 Political parties 45,920 Prices 45,356 Politicians 44,624 Police 41,556 Peace 40,213 Political and social views 38,682 Painters 38,528 Physicians 37,816 Printing 37,652 Photography 37,513 Penn dissertations 37,109 Public lands 36,322 Plants 34,601 Private collections 32,529 Public welfare 31,674 Poverty 31,205 Political participation 30,638 Poor 30,280 Paleontology 30,142 Personnel management 29,054 Physiology 29,037 Publishers and publishing 27,811 Petroleum industry and trade 27,740 Philosophie 26,987 Popular culture 26,585 Psychoanalysis 25,567 Public administration 25,025 Postal service 24,998 Prisons 24,113 People with disabilities 23,974 Power resources 23,835 Patients 22,556 Painting, Chinese 22,432 Pensions 21,945 Public buildings 21,944 Physiological effect 21,847 Petroleum 21,127 Political corruption 20,933 Public Policy 20,864 Philosophers 20,397 Protection 20,027 Philosophy, Modern 19,550 Prisoners 19,353 Psychotherapy 19,102 Political prisoners 19,009 Prayer 18,943 Peasants 18,793 Portraits 18,640 Painting, Modern 18,544 Piano, Musique de 18,458 Political culture 17,941 Politics, Practical 17,745 Psychiatry 17,564 Penn theses 17,263 Production and direction 16,984 Palestinian Arabs 16,773 Philosophy, Chinese 16,711 Public schools 16,222 Psalms (Music) 15,797 PSYCHOLOGY 15,626 Public Health 15,613 Piano music, Arranged 15,296 Public works 15,269 Public contracts 15,045 Power (Social sciences) 14,822 Politique gouvernementale 14,717 Phonology 14,607 Press 14,527 Philosophy, Ancient 14,435 Physical geography 14,341 Piano trios 14,023 Personal narratives 13,728 PHILOSOPHY 13,672 Painting, Italian 13,479 Poetics 13,437