SpaceFusion: A Multi-Server Architecture for Shared Virtual Environments. - Hiroyasu Sugano; Koji Otani; Haruyasu Ueda; Shinichi Hiraiwa; Susumu Endo; Youji Kohda (VRML, 1997)

A Model for Presence and Instant Messaging. - Mark Day; Jonathan D. Rosenberg; Hiroyasu Sugano (RFC, 2000)

Presence Information Data Format (PIDF). - Hiroyasu Sugano; Shingo Fujimoto; Graham Klyne; Adrian Bateman; Wayne Carr; Jon Peterson (RFC, 2004)