Classification
LCK - Ecology - general aspects
UHP - Protection of nature and landscape
4
UEA - Environmental policy and economy - general aspects
2
AFK - Research institutions - Germany
1
GPA - Geobiology - general
1
GPAB - Flora, vegetation - geographical aspects
1
LAL - Biology - general aspects
1
LWF - Agriculture - methods
1
UCA - Environmental problems, man and environment - general aspects
1
UCE - Environmental impact, environmental pollution
1
UED - Environmental policy
1
UEF - Sustainability
1
UEND - Environmental costs, environmental investments
1
UHC - Area planning and environment
1
YRA - Social studies
1