Columbia subject headings:
Fischborn, Gottfried, 1936---Correspondence.
Hacks, Peter, 1928-2003--Correspondence.
Harvard subject headings:
Fischborn, Gottfried, 1936---Correspondence.
Hacks, Peter, 1928-2003--Correspondence.
Hacks, Peter, 1928-2003--Interviews.
Princeton subject headings:
Fischborn, Gottfried, 1936---Correspondence.
Hacks, Peter, 1928-2003--Correspondence.