RAGAUSKIENĖ, Raimonda. When Religious Views Become Irrelevant. The Physicians of the Protestants – Mikołaj the Black Radziwiłł (1515–1565) and the Biržai-Dubingiai Line of the Radziwiłł Family. Rocznik Lituanistyczny. Online. 19 September 2020. Vol. 6, pp. 77-94. [Accessed 2 July 2025]. DOI 10.12775/RL.2020.6.04.