Classification
ESB - Hydrogen energy
7
ETF - Fuel cells - general
4
ETA - Energy storage
2
TKJ - Traffic
2
UHK - Traffic and environment - incl. automobile exhaust gas
2
CXX - Hydrogen production - chemistry and technology
1
EHA - Renewable energy sources
1
ESA - Synthetic fuels - utilization
1
EVA - Energy demand, energy supply - comprehensive works
1
EVB - Energy supply of Germany
1
EWA - Energy economy
1
EXA - Energy policy
1