Classification
EAA - Energy - reference books
92
TAA - Engineering sciences - reference books
14
CAA - Chemistry - reference books
11
DAA - Information technology - reference books
11
EWA - Energy economy
11
GAA - Geosciences - reference books
11
LAA - Biology - reference books
11
PAA - Physics - reference books
11
HAA - Medicine - reference books
8
EXA - Energy policy
7
AQPD - Bibliographies of theses / dissertations
5
AZZ - Firm index - general
5
EHA - Renewable energy sources
4
EVA - Energy demand, energy supply - comprehensive works
4
UAA - Environment - reference books
4
EFA - Petroleum, natural gas
3
EPK - Nuclear energy
3
YAA - Law, economy, social affairs - reference books
3
EAA - Energy - reference books
2
EFP - Petroleum production, natural gas production
2
DAA - Information technology - reference books
1
EPK - Nuclear energy
1
EUA - Energy conservation - general
1
FAA - Materials research - reference books
1
FAF - Materials research - comprehensive works
1
GWBA - Raw material resources, raw material reserves
1
MAA - Mathematics - reference books
1
TAA - Engineering sciences - reference books
1
YPA - Economy - encyclopaedic glossaries
1