Andreeva, N.V., Serov, N.I. and Tulupova, L.O. (2000) “$Q$-conditional symmetry of a nonlinear two-dimensional heat-conduction equation”,
Ukrains’kyi Matematychnyi Zhurnal, 52(6), pp. 846–849. Available at:
https://umj.imath.kiev.ua/index.php/umj/article/view/4481 (Accessed: 26 April 2025).