MLA

Wat, Aleksander, 1900-1967. "Ostatni zeszyt," notebook. Box 32, folder 756. 1967. https://collections.library.yale.edu/catalog/2054648.

APA, 6th edition

Wat, Aleksander, 1900-1967. (["Box 32, folder 756"])(1967)["Ostatni zeszyt," notebook]. https://collections.library.yale.edu/catalog/2054648.