Czakon, Dominika, Natalia Anna Michna, и Leszek Sosnowski, ред. «On the Difficult Academic and Personal Relationship of Roman Ingarden and Kazimierz Twardowski . 63». в Roman Ingarden and His Times. Poland: Księgarnia Akademicka Publishing, 2020. просмотрено ноябрь 5, 2026. https://books.akademicka.pl/publishing/catalog/book/83/chapter/1060.