D. Anil Kumar , G. Surya Narayana , Dr. M. Rudra Kumar. “Predicting User Geographical Service Rating in Social Network Using Point of Interest Recommendation”. International Journal of Emerging Trends in Science and Technology, Vol. 4, no. 09, Sept. 2017, pp. 5898-04, http://igmpublication.org/ijetst.in/index.php/ijetst/article/view/1390.