Letter from Stanisław Ignacy Witkiewicz written 26.04.1935

Letter to the Committee of the Library of Classics of Philosophy written 03.12.1968

Letter from Anna Teresa Tymieniecka written n/d 1

Application for the appointment as professor written 11.02.1931

Letter to Kazimierz Twardowski written 13.08.1928

Letter from Irena Krońska written in 06.01.1947