1. Y. Kanagawa, K. Hayashi, M. Shibuya and T. Yasujima,J. Industrial Wood of Japan 47, 100 (1992).
2. H. Saiki,The structure of Domestic and Imported Woods in Japan (An Atlas of Scanning Electron Micrographs), Japan Forest Technical Association (1982).
3. S. Itoh, Y. Nadamitsu, S. Nagano and M. Fujita,J. Jpn. Explosives Soc. 58, 189 (1997).