“…Recommender systems have been used to recommend movies (Wu & Niu, 2015), research papers (Beel, Gipp, Langer, & Breitinger, 2015), collaborators (Yan & Guns, 2014), experts (Protasiewicz et al, 2016), reviewers (Basu, Cohen, Hirsh, & Nevill-Manning, 2001), citations (Caragea, Silvescu, Mitra, & Giles, 2013), and tags (Song, Zhang, & Giles, 2011).…”