MELIK-ADAMYAN, Perch. On Nagy-Foias Characteristic Function in Extensions Theory of Hermitian Operators. Armenian Journal of Mathematics, Yerevan, Armenia, v. 8, n. 1, p. 1–24, 2016. Disponível em: https://armjmath.sci.am/index.php/ajm/article/view/120. Acesso em: 4 apr. 2025.