Columbia subject headings:
Harvard subject headings:
Biodiversity conservation--Europe, Central--Congresses.
Biodiversity conservation--Europe, Eastern--Congresses.
Natural areas--Europe, Central--Congresses.
Natural areas--Europe, Eastern--Congresses.
Princeton subject headings:
Biodiversity conservation--Congresses.
Biodiversity conservation--Europe, Eastern--Congresses.
Natural areas--Europe, Eastern--Congresses.