Blackmore, D., A. K. Prykarpatsky, Ya. A. Prykarpatsky, and A. M. Samoilenko. “Theory
of
Multidimensional
Delsarte
–
Lions
Transmutation
Operators.
II”.
Ukrains’kyi Matematychnyi Zhurnal 71, no. 6 (June 25, 2019): 808–839. Accessed April 11, 2025.
https://umj.imath.kiev.ua/index.php/umj/article/view/1478.