Columbia subject headings:
Hirschfeld, Magnus, 1868-1935--Congresses.
Sexology--Germany--Congresses.
Harvard subject headings:
Hirschfeld, Magnus, 1868-1935--Congresses.
Sexology--Germany--Congresses.
Princeton subject headings:
Hirschfeld, Magnus, 1868-1935--Congresses.
Sexology--Germany--Congresses.