Koji Kamei Tetsushi Ikeda Hiroyuki Kidokoro Masayuki Shiomi Akira Utsumi Kazuhiko Shinozawa Takahiro Miyashita Norihiro Hagita Effectiveness of Cooperative Customer Navigation from Robots around a Retail Shop. 235-241 2011 SocialCom/PASSAT http://doi.ieeecomputersociety.org/10.1109/PASSAT/SocialCom.2011.173 conf/socialcom/2011 db/conf/socialcom/socialcom2011.html#KameiIKSUSMH11