Technology: general issues 32 History of engineering & technology 27 Research & information: general 21 Information technology industries 8 Other technologies & applied sciences 7 Energy industries & utilities 4 Humanities 4 Mathematics & science 4 Medicine 4 Computer vision 3 Geography 3 Science: general issues 3 Social interaction 3 The arts 3 Artificial intelligence 2 Automatic control engineering 2 Computer networking & communications 2 Mobile phone technology 2 Music 2 Oceanography (seas) 2 Philosophy: aesthetics 2 Theory of music & musicology 2 20th century & contemporary classical music 1 20th century history: c 1900 to c 2000 1 Acoustic & sound engineering 1 Anthologies (non-poetry) 1 Audiology & otology 1 Automotive technology & trades 1 Biology, life sciences 1 Circuits & components 1