Hamaekers, Hubert. “Prof. Wlodzimierz Nykiel 70: From Cooperation to Friendship”. In Challenges of Contemporary Tax Law: Jubilee Book Dedicated to Professor Włodzimierz Nykiel. Volume II, edited by Ziemowit Kukulski and Małgorzata Sęk, 39–43. Poland: Lodz University Press, 2024. Accessed January 25, 2026. https://www.press.uni.lodz.pl/index.php/wul/catalog/book/1154/chapter/3152.