Walid Saad Zhu Han Are Hjørungnes Dusit Niyato Ekram Hossain Coalition Formation Games for Distributed Cooperation Among Roadside Units in Vehicular Networks. 48-60 2011 29 IEEE Journal on Selected Areas in Communications 1 http://dx.doi.org/10.1109/JSAC.2011.110106 db/journals/jsac/jsac29.html#SaadHHNH11