Classification
YPB - Economy - general aspects
5
UEA - Environmental policy and economy - general aspects
3
UEN - Environmental economy
3
UMV - Climatic change
3
YPO - Economic policy
3
YRA - Social studies
2
UCN - Environmental education
1
UED - Environmental policy
1
UKA - Environmental damage and energy production
1
USGT - Waste prevention
1
YRB - Social sciences, sociology
1