Columbia subject headings:
Harvard subject headings:
Forest management--Baltic Sea Region--Congresses--History.
Forest management--North Sea Region--Congresses--History.
Forests and forestry--Baltic Sea Region--Congresses--History.
Forests and forestry--North Sea Region--Congresses--History.
Sustainable development--Baltic Sea Region--Congresses--History.
Sustainable development--North Sea Region--Congresses--History.
Timber--Baltic Sea Region--Congresses--History.
Timber--North Sea Region--Congresses--History.
Princeton subject headings:
Sustainable development--Congresses--History--19th century.