Barbulyak, V.S. and Kondratiev, Y.G. (1993) “Periodic Gibbs states”, Ukrains’kyi Matematychnyi Zhurnal, 45(4), pp. 451–458. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/5831 (Accessed: 14 April 2025).