At the end of the war he returned to continue his work at the University of Warsaw, also undertaking research at the Universities of Kazan and Cracow. However the death of his father forced him to take a break from his studies and researches.
Sa katapusan ng digmaan siya ibabalik na magpatuloy sa kanyang trabaho sa University of Warsaw, din pagsasagawa ng pananaliksik sa Unibersidad ng Kazan at Cracow. Subalit ang kamatayan ng kanyang ama sa kanya upang sapilitang kumuha ng break mula sa kanyang pag-aaral at pananaliksik.