BARBIR, A.; HIMMELREICH, Kruli´c K.; PEČARIĆ, J. E. Refinements of Jessen’s functional. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 68, n. 7, p. 879–896, 2016. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1888. Acesso em: 5 dec. 2025.