Classification
EHA - Renewable energy sources
28
EVA - Energy demand, energy supply - comprehensive works
8
EVN - Energy supply - future aspects
6
EWA - Energy economy
2
AJA - Directories - general
1
AZZ - Firm index - general
1
FNP - Ceramics - specific materials
1
FNX - Carbon, carbon materials
1
LWO - Agricultural ecology, sustainable agriculture
1
TEDD - Electric power transmission
1