Y. Okamoto

发表

A. Danilewsky, K. Benz, T. Nishinaga, 1992 .

Y. Akimune, N. Hirosaki, F. Munakata, 1996 .

Y. Akimune, N. Hirosaki, M. Tanimura, 1994 .

Tetsuo Yamada, Y. Akimune, N. Hirosaki, 1995 .