HUNG, C. An Enclosed Line Forming Three Planes Perpendicular To Each Other In A Symmetrical Order. The Capilano Review, [S. l.], v. 1, n. 12, p. 224–226, 1977. Disponível em: https://journals.sfu.ca/capreview/index.php/capreview/article/view/693. Acesso em: 3 may. 2024.