Columbia subject headings:
Horkheimer, Max, 1895-1973--Bibliography.
Horkheimer, Max, 1895-1973--Interviews.
Horkheimer, Max, 1895-1973--Travel--Italy.
Harvard subject headings:
Horkheimer, Max, 1895-1973--Bibliography.
Horkheimer, Max, 1895-1973--Interviews.
Horkheimer, Max, 1895-1973--Journeys--Italy.
Princeton subject headings:
Horkheimer, Max, 1895-1973--Bibliography.
Horkheimer, Max, 1895-1973--Interviews.
Horkheimer, Max, 1895-1973--Travel--Italy.