Filipe Araújo Luís Rodrigues GeoPeer: A Location-Aware Peer-to-Peer System. 39-46 2004 conf/nca/2004 NCA http://csdl.computer.org/comp/proceedings/nca/2004/2242/00/22420039abs.htm db/conf/nca/nca2004.html#AraujoR04