Columbia subject headings:
Harvard subject headings:
Feyerabend, Paul, 1924-1994--Correspondence.
Hoyningen-Huene, Paul, 1946---Correspondence.
Philosophers--Austria--Correspondence.
Philosophers--Germany--Correspondence
Princeton subject headings:
Feyerabend, Paul, 1924-1994--Correspondence.
Hoyningen-Huene, Paul, 1946---Correspondence.
Philosophers--Germany--Correspondence.