Nakhaei Rad, Z., Zandhessami, H., & Tolouei Ashlaghi, A. "Improving Collaborative Filtering Recommender System Results and Performance using Combination of Fuzzy Grey Wolf Optimizer Algorithm and Lion Optimization Algorithm", Journal of Industrial Management Perspective, 11, 4, 2021, 197–222. doi: 10.52547/JIMP.11.4.197