Columbia subject headings:
Harvard subject headings:
Frege, Gottlob, 1848-1925--Congresses.
Logic, Symbolic and mathematical--Congresses
Philosophers--Germany--Congresses.
Philosophy, German--Congresses.
Princeton subject headings:
Festschriften.
Frege, Gottlob, 1848-1925--Congresses.
Logic, Symbolic and mathematical--Congresses.
Philosophers--Germany--Congresses.
Philosophy, German--Congresses.