Classification
AHC - Research and development, research politics - Germany
4
YZA - Politics, political science
4
AHA - Research and development, research politics - general
3
AHM - Theory of science
2
AHE - Research and development, research politics - foreign countries
1
AHF - Research and science
1
AHP - Philosophy
1
AXA - Geographic surveys - specific countries
1
EXA - Energy policy
1
UED - Environmental policy
1
YPB - Economy - general aspects
1
YPG - Business management
1