SZCZAWIŃSKA, Joanna. Selections of biadditive set-valued functions. Annales Mathematicae Silesianae, [S. l.], v. 8, p. 227–240, 1994. Disponível em: https://trrest.vot.pl/ojsus/index.php/AMSIL/article/view/14238. Acesso em: 7 may. 2025.