Columbia subject headings:
Interpersonal relations.
Marriage.
Unmarried couples.
Harvard subject headings:
Families--Economic aspects--United States.
Marriage--United States.
Married people--Employment--Social aspects--United States.
Sex in marriage--United States.
Unmarried couples--United States.
Princeton subject headings:
Interpersonal relations.
Marriage--United States.
Unmarried couples--United States.