“Steen – Ermakov – Pinney Equation and Integrable Nonlinear Deformation of One-Dimensional Dirac Equation”. Neliniini Kolyvannya 20, no. 2 (June 29, 2017): 267–273. Accessed April 12, 2026. https://nosc.imath.kiev.ua/index.php/nosc/article/view/867.