Columbia subject headings:
Meinong, A. (Alexius), 1853-1920--Correspondence.
Twardowski, Kazimierz, 1866-1938--Correspondence.
Harvard subject headings:
Meinong, A. (Alexius), 1853-1920--Correspondence.
Philosophers--Austria--Correspondence.
Philosophers--Poland--Correspondence.
Twardowski, Kazimierz, 1866-1938--Correspondence.
Princeton subject headings:
Meinong, A. (Alexius), 1853-1920--Correspondence.
Twardowski, Kazimierz, 1866-1938--Correspondence.