S. A. . Globa, “One class of models of quantum grid systems and their Gibbs states”, Ukr. Mat. Zhurn., vol. 40, no. 6, pp. 787–792, Nov. 1988, Accessed: Dec. 06, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/9293