Henri, J., J. . Azimi, B. C. . Chenwi, and N. . Isidore. “Visualizing and Optimizing Portfolio With Nonlinear Transaction Costs and Specific Constraints”. European Journal of Applied Sciences, vol. 7, no. 6, Feb. 2020, pp. 05-16, https://journals.scholarpublishing.org/index.php/AIVP/article/view/7530.