Weak rock :  soft, fractured and weathered rock proceedings of the International Symposium on Weak Rock, Tokyo, 21-24 September 1981 / 
edited by Koichi Akai, Masao Hayashi, Yuichi Nishimatsu. 
 - Rotterdam :  A. A. Balkema,  1981. 
 - 3 volume :  illustrations ;  26 cm. 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>ISBN: </label>9061912091 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Rock mechanics--Congresses.