Rubuta ci gaba don wannan sakin layi - An buga babban aikinsa na ƙarshe, "Historia Polski 1914 <unk> 1939" ("Tarihin Poland 1914-1939"), bayan mutuwarsa. Sakamakon murkushewar gwamnati a kan 'yan adawa an yi wa littafin takunkumi sosai, amma ba da daɗewa ba an fahimci ɓoyewar ɓoye a cikin "bibuła" (Rasha "samizdat"). Tsinkayar littattafansa misali ne mai kyau na matsalar da masana tarihi ke fuskanta a karkashin gwamnatocin da ke tsoma baki cikin aikin ilimi. Musamman, kulawar kwaminisanci na Poland ta cire duk wani ambaton yarjejeniyar Molotov-Ribbentrop (Jamus ta Nazi-Soviet) da kuma sashin da Soviet ta mamaye Poland a ranar 17 ga Satumba 1939 tare da hoton faretin sojan Jamus da Soviet a Brest-Litovsk
an cire kuma an maye gurbinsa da bayanin kula na gaba ɗaya akan iyakokin da aka canza.