Ogunsola, Olufemi J., and Ifeyinwa E. Daniel. “Pseudo-Amenability and Pseudo-Contractibility of Restricted Semigroup Algebra”. Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica 17 (December 7, 2018): 89–102. Accessed September 20, 2026. https://studmath.uken.krakow.pl/article/view/12963.