Columbia subject headings:
Harvard subject headings:
Apitzsch, Georges--Correspondence.
Gay men--Germany--Correspondence.
Homosexuality--Europe--History.
Lacassagne, A. (Alexandre), 1843-1924--Correspondence.
Princeton subject headings:
Apitzsch, Georges--Correspondence.
Apitzsch, Georges.
Homosexuality.
Lacassagne, A. (Alexandre), 1843-1924--Correspondence.