Classification
UCN - Environmental education
UCA - Environmental problems, man and environment - general aspects
4
UCL - Environmental research
2
HDG - Psychology, psychiatry
1
UCJ - Environmental protection - general aspects
1
UED - Environmental policy
1
UEN - Environmental economy
1
USGT - Waste prevention
1
UVC - Environmental chemicals, hazardous materials - general aspects
1
YPO - Economic policy
1
YRA - Social studies
1
YRB - Social sciences, sociology
1