Tomohiro Akagawa Takuji Narumi Young Ah Seong Takashi Kiriyama Characterizing the Space by Presenting Non-visual Information. 271-282 2009 LoCA http://dx.doi.org/10.1007/978-3-642-01721-6_17 conf/loca/2009 db/conf/loca/loca2009.html#AkagawaNSK09