Columbia subject headings:
Harvard subject headings:
Botanical libraries--Congresses.
Botany--Germany--Hannover (Province)--History--Congresses.
Dumbarton Oaks. Garden Library--Congresses.
Gardens--Germany--Hannover (Province)--History--Congresses.
Herrenhäuser Gärten (Hannover, Germany)--Congresses.
Libraries--Special collections--Gardens--Congresses.
Princeton subject headings:
Botanical libraries.
Botany--Germany--Hannover (Province)--History.
Gardens--Germany--Hannover (Province)--History.
Herrenhäuser Gärten (Hannover, Germany)