Americans Documentary films 701 History, Modern 700 History 689 Foreign study 292 Current affairs 263 Social sciences 255 更多 ... Enthnology 244 Sociology 195 Ethnicity 189 Travel 168 Political science 151 History, Military 127 Slavery 120 Social life and customs 104 Artists 103 Criminal law 103 Indigenous peoples 93 Television series 73 Description and travel 71 Science 71 Intellectual life 69 Health 67 Arts 66 Authors, American 65 Human rights 63 Mass media and culture 61 Music 61 Economics 56 Race 55 少 ...