Inmaculada Espejo Alfredo Marín Justo Puerto Antonio M. Rodríguez-Chía A comparison of formulations and solution methods for the minimum-envy location problem. 1966-1981 2009 36 Computers & OR 6 http://dx.doi.org/10.1016/j.cor.2008.06.013 db/journals/cor/cor36.html#EspejoMPR09