T. Kántor, “Mathematical Doctoral School of the Mathematical Seminar of the University of Debrecen at the beginning of the 20th century (Debrecen, 1927-1940)”, Teach. Math. Comp. Sci., vol. 16, no. 2, pp. 195–214, Dec. 2018, doi: 10.5485/TMCS.2018.0450.