Classification
LWO - Agricultural ecology, sustainable agriculture
4
UEF - Sustainability
UEN - Environmental economy
3
AHZ - History of science and technology
1
EWA - Energy economy
1
GWA - Raw material economy, raw material policy
1
LWE - Agriculture - general aspects
1
UEA - Environmental policy and economy - general aspects
1
YPB - Economy - general aspects
1