NAZAROVA, L. A.; ROITER, A. V. The Norm of a Relation, Separating Functions, and Representations of Marked Quivers. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 54, n. 6, p. 808–840, 2002. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4119. Acesso em: 5 dec. 2025.