1. T. G. Zimmerman: IBM Syst. J. 35 (1996) 609.
2. A. Furuya, A. Sasaki, H. Morimura, K. Aihara, and M. Shinagawa: Proc. ISOM 2012, 2012, p. 108.
3. M. Shinagawa, A. Sasaki, A. Furuya, H. Morimura, and K. Aihara: Proc. ISOM 2012, 2012, p. 106.
4. N. Matsushita, S. Tajima, Y. Ayatsuka, and J. Rekimoto: Proc. 4th Int. Symp. Wearable Computers, 2000, p. 119.
5. K. Partridge, B. Dahlquist, A. Veisch, A. Cain, A. Foreman, J. Goldberg, and G. Borriello: Proc. ACM Symp. User Interface Software and Technology, 2001, p. 183.