MELIKADAMYAN, Perch. On Characteristic Function of a Contraction, Its Model and Function of Strauss. Armenian Journal of Mathematics, Yerevan, Armenia, v. 9, n. 2, p. 93–101, 2017. Disponível em: https://armjmath.sci.am/index.php/ajm/article/view/151. Acesso em: 3 apr. 2025.