Amerov, T. K., N. I. Serov, and V. I. Fushchich. 1993. “Nonlocal Ansatze and Solutions of a Nonlinear System of Heat-Conduction Equations”. Ukrains’kyi Matematychnyi Zhurnal 45 (2): 293–302. https://umj.imath.kiev.ua/index.php/umj/article/view/5812.