Zeb, Anwar, Fiza Bibi, and Gul Zaman. “Optimal Control Strategies in Square Root Dynamics of Smoking Model”. International Journal of Scientific World 3, no. 1 (March 10, 2015): 91–97. Accessed November 24, 2024. https://sciencepubco.com/index.php/IJSW/article/view/4138.