Diaries, letters & journals 17 History 16 Literature: history & criticism 13 Mathematics 12 linguistics 12 Literary studies: c 1500 to c 1800 10 Western philosophy: Medieval & Renaissance, c 500 to c 1600 10 Literary studies: plays & playwrights 9 Literature & literary studies 9 Philosophy 9 Research & information: general 8 Science: general issues 8 Sociology 8 History of mathematics 7 Church history 6 European history 6 History of engineering & technology 6 Modern history to 20th century: c 1700 to c 1900 6 Social & cultural history 6 Early modern history: c 1450/1500 to c 1700 5 Education 5 Ethics & moral philosophy 5 Language: reference & general 5 Literary studies: poetry & poets 5 Medicine 5 Physics 5 Technology: general issues 5 Western philosophy: c 1600 to c 1900 5 Computer vision 4 Historical & comparative linguistics 4