Nteumagne, Bienvenue Feugang, and Raseelo J. Moitsheki. “Optimal Systems and Group Invariant Solutions for a Model Arising in Financial Mathematics”. Mathematical Modelling and Analysis 14, no. 4 (December 31, 2009): 495-502. Accessed April 26, 2024. https://journals.vilniustech.lt/index.php/MMA/article/view/6572.