Ger, J. (1985) “On analytic solutions of the equation ϕ(f(x)) = g(x,ϕ(x)) (III)”, Annales Mathematicae Silesianae, 1, pp. 93–102. Available at: https://trrest.vot.pl/ojsus/index.php/AMSIL/article/view/14339 (Accessed: 6 May 2025).