Effects of Touch Behaviors and Whispering Voices in Robot-Robot Interaction for Information Providing Tasks. - Yuka Okada; Riko Taniguchi; Akihiro Tatsumi; Masashi Okubo; Mitsuhiko Kimoto; Takamasa Iio; Katsunori Shimohara; Masahiro Shiomi (RO-MAN, 2020)