KEI-time traveler: visiting a past world with mobile phones to enhance learning motivation. - Hiroyuki Tarumi; Keitaro Yamada; Takafumi Daikoku; Fusako Kusunoki; Shigenori Inagaki; Makiko Takenaka; Toshihiro Hayashi; Masahiko Yano (IDC, 2008)

KEI-Time Traveler: A Virtual Time Machine with Mobile Phones for Learning Local History. - Hiroyuki Tarumi; Keitaro Yamada; Takafumi Daikoku; Fusako Kusunoki; Shigenori Inagaki; Makiko Takenaka; Toshihiro Hayashi; Masahiko Yano (Trans. Edutainment, 2009)