@preprint{beel2013research, author = {Beel, Joeran and Langer, Stefan and Genzmehr, Marcel and Gipp, Bela and Breitinger, Corinna and Nürnberger, Andreas}, interhash = {544758b1fd737c010643f529c4f48ae6}, intrahash = {4afa2bd342dda6b6d32713aa0fbc33bd}, title = {Research Paper Recommender System Evaluation: A Quantitative Literature Survey}, year = 2013 }