http://www.white.umic.jp/pc/files/petitcom-3ddanjon-text1.pdf http://www.white.umic.jp/pc/files/petitcom-3ddanjon-text2.pdf http://www.white.umic.jp/pc/files/petitcom-3ddanjon-text3.pdf http://www.white.umic.jp/pc/files/petitcom-3ddanjon-text4.pdf