Columbia subject headings:
Interpersonal relations--Congresses.
Love--Congresses.
Love--Psychological aspects--Congresses.
Harvard subject headings:
Interpersonal relations--Congresses
Love--Congresses
Love--Psychological aspects--Congresses.
Princeton subject headings:
Interpersonal relations--Congresses.
Love--Congresses.
Love--Psychological aspects--Congresses.