Columbia subject headings:
Love.
Middle class--Europe--History--19th century.
Middle class--United States--History--19th century.
Psychoanalysis and culture.
Sex (Psychology)
Sex customs--Europe--History--19th century.
Sex customs--United States--History--19th century.
Harvard subject headings:
Love
Middle class--Europe--History--19th century.
Middle class--United States--History--19th century.
Psychoanalysis and culture.
Sex (Psychology)
Princeton subject headings: