GRYSHCHUK, S. V. Сommutative сomplex algebras of the second rank with unity and some cases of plane orthotropy. I. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 70, n. 8, p. 1058–1071, 2018. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1617. Acesso em: 27 apr. 2025.