Brzeziński B, Nowak I. “Behavioural letters” and the question of the legal basis of the National Revenue Administrationʼs operation. SPE [Internet]. 2024 Jul. 25 [cited 2024 Jul. 27];131:29-55. Available from: https://journals.ltn.lodz.pl/Studia-Prawno-Ekonomiczne/article/view/2408