APA
Akai K., Hayashi M. & Nishimatsu Y. (1981). Weak Rock : soft, fractured and weathered rock : proceedings of the international symposium on weak rock, Tokyo, 21-24 September 1981. Rotterdam: A.A. Balkema.
Chicago
Akai Koichi, Hayashi Masao and Nishimatsu Yuichi. 1981. Weak Rock : soft, fractured and weathered rock : proceedings of the international symposium on weak rock, Tokyo, 21-24 September 1981. Rotterdam: A.A. Balkema.
Harvard
Akai K., Hayashi M. and Nishimatsu Y. (1981). Weak Rock : soft, fractured and weathered rock : proceedings of the international symposium on weak rock, Tokyo, 21-24 September 1981. Rotterdam: A.A. Balkema.
MLA
Akai Koichi, Hayashi Masao and Nishimatsu Yuichi. Weak Rock : soft, fractured and weathered rock : proceedings of the international symposium on weak rock, Tokyo, 21-24 September 1981. Rotterdam: A.A. Balkema. 1981.