Petrina, D. Y. (2001) “Spectrum and States of the BCS Hamiltonian in a Finite Domain. II. Spectra of Excitations”, Ukrains’kyi Matematychnyi Zhurnal, 53(8), pp. 1080-1100. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/4328 (Accessed: 30May2024).