1.
Skrypnik WI. On the Evolution Operator of the Gradient Diffusion Hierarchy for Plane Rotators. Ukr. Mat. Zhurn. [Internet]. 2001 Dec. 25 [cited 2025 Dec. 5];53(12):1664-85. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/4386