VARBANOV, Z. Some results for identification for sourses and its extension to liar models. Ann. Sofia Univ. Fac. Math. and Inf., [S. l.], v. 99, p. 69–73, 2009. Disponível em: https://ftl5.uni-sofia.bg/index.php/fmi/article/view/112. Acesso em: 4 dec. 2024.