Object-based Navigation: An Intuitive Navigation Style for Content-Oriented Integration Environment. - Kyoji Hirata; Sougata Mukherjea; Yusaku Okamura; Wen-Syan Li; Yoshinori Hara (Hypertext, 1997)

Facilitating Object-Based Navigation Through Multimedia Web Databases. - Kyoji Hirata; Sougata Mukherjea; Wen-Syan Li; Yusaku Okamura; Yoshinori Hara (Theory Pract. Object Syst., 1998)

Optimization of xDSL transmission systems. - Yusaku Okamura; Hiroshi Okado; Tetsu Koyama (ICC, 1999)