An effective user clustering-based collaborative filtering recommender system with grey wolf optimisation. - Sivaramakrishnan Natarajan; V. Subramaniyaswamy 001; Logesh Ravi; Varadarajan Vijayakumar 001; Xiao-Zhi Gao 001; S. L. Rakshana Sri (Int. J. Bio Inspired Comput., 2020)