BAHYRYCZ, A. On systems of equations with unknown multifunctions related to the plurality function. Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica, [S. l.], v. 9, p. 133–142, 2011. Disponível em: https://studmath.uken.krakow.pl/article/view/13251. Acesso em: 31 oct. 2026.