Columbia subject headings:
Endorphins--Analysis--Congresses.
Endorphins--Physiological effect--Congresses.
Endorphins--Synthesis--Congresses.
Harvard subject headings:
Endorphins--Analysis--Congresses.
Endorphins--Physiological effect--Congresses.
Endorphins--Synthesis--Congresses.
Princeton subject headings:
Endorphins--Analysis--Congresses.
Endorphins--Physiological effect--Congresses.
Endorphins--Synthesis--Congresses.