History 386 Study and teaching 348 Social life and customs 128 Education 125 Manners and customs 121 Vietnam War, 1961-1975 113 Activity programs 96 more ... Teachers 95 Hunting 92 Rural families 92 Self-reliant living 92 Survivalism 92 Wilderness areas 92 Science 87 Animals 80 World War, 1939-1945 77 Politics and government 74 Career development 71 Training of 66 Teaching 63 Criminal investigation 58 Mathematics 56 Conduct of life 53 Students 53 Murder 51 Technology 51 Classroom management 49 Civilization 48 Criminals 46 Prisoners 46 less ...