Columbia subject headings:
Antihistamines--Congresses.
Histamine--Receptors--Congresses.
Peptic ulcer--Chemotherapy--Congresses.
Harvard subject headings:
Antihistamines--Congresses.
Gastrointestinal system--Congresses.
Histamine--Receptors--Congresses.
Peptic ulcer--Chemotherapy--Congresses.
Princeton subject headings: