Classification
UEDM - Policy of clean air
13
UMV - Climatic change
4
YZA - Politics, political science
3
UED - Environmental policy
2
EXA - Energy policy
1
UCJ - Environmental protection - general aspects
1
UEDK - Policy of radioactive waste
1
UENH - Cost factors of air pollution and control
1
UMEE - Clean air planning
1
UMG - Technology of clean air
1
YDG - Tax legislation
1
YED - Law on clean air
1
YPO - Economic policy
1