GOEBEL, Kazimierz. “Remarks on Fixed Point Sets: Dedicated to Professor Ioan A. Rus on the Occasion of His 80th Anniversary”. Studia Universitatis Babeș-Bolyai Mathematica, vol. 61, no. 4, Dec. 2016, pp. 429-34, https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/5630.