Aragón, V. S., S. C. Esquivel, and C. Coello Coello. “Optimizing Constrained Problems through a T-Cell Artificial Immune System”. Journal of Computer Science and Technology, vol. 8, no. 03, Oct. 2008, pp. p. 158-165, https://journal.info.unlp.edu.ar/JCST/article/view/758.