PETRINA, E. D.; PETRINA, D. Ya. Existence of equilibrium states of systems of hard spheres in the Boltzmann-Enskog limit within the frame work of the grand canonical ensemble. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 49, n. 1, p. 112–121, 1997. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4990. Acesso em: 5 dec. 2025.