Wahdan, H. G., H. E. Abdelslam, T. H. M. Abou-El-Enien, and S. S. Kassem,  "Discretization of Emperor Penguins Colony Algorithms with Application to Modular Product Design",  Journal Européen des Systèmes Automatisés, vol. 54, no. 1, pp. 35?44, 2021.