Columbia subject headings:
Alkaloids--Congresses.
Botanical chemistry--Congresses.
Isoquinoline--Congresses.
Plants--Composition--Congresses.
Harvard subject headings:
Alkaloids--Congresses.
Botanical chemistry--Congresses.
Isoquinoline--Congresses.
Plants--Composition--Congresses.
Princeton subject headings:
Alkaloids--Congresses.
Botanical chemistry--Congresses.
Isoquinoline--Congresses.
Plants--Composition--Congresses.