Jachimowski, Marek, et al. “In Memoriam: Marian Gierula (1955 – 2020); Michał Gajlewicz (1946–2020); Zbigniew Oniszczuk (1955–2020); Piotr Francuz (1960–2020)”. Central European Journal of Communication, vol. 13, no. 3(27), Jan. 2021, pp. 481-9, https://journals.ptks.pl/cejc/article/view/206.