Taisuke Izumi Samia Souissi Yoshiaki Katayama Nobuhiro Inuzuka Xavier Défago Koichi Wada Masafumi Yamashita The Gathering Problem for Two Oblivious Robots with Unreliable Compasses http://arxiv.org/abs/1111.1492 2011 CoRR abs/1111.1492 db/journals/corr/corr1111.html#abs-1111-1492