PASTECZKA, P. Jensen-type geometric shapes. Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica, [S. l.], v. 19, p. 27–33, 2020. Disponível em: https://studmath.up.krakow.pl/article/view/7120. Acesso em: 6 dec. 2023.