PETRINA, D. Ya. BCS Model Hamiltonian of the Theory of Superconductivity as a Quadratic Form. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 56, n. 3, p. 309–338, 2004. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3756. Acesso em: 27 apr. 2025.