Nikitin, A.G. and Popovich, R.O. (2001) “Group Classification of Nonlinear Schrödinger Equations”,
Ukrains’kyi Matematychnyi Zhurnal, 53(8), pp. 1053–1060. Available at:
https://umj.imath.kiev.ua/index.php/umj/article/view/4326 (Accessed: 10 April 2025).