International symposium on underground engineering :  proceedings / 
editor, B. Singh. 
 - Rotterdam :  A.A. Balkema,  1989. 
 - 2 v. :  ill. 
<br/><br/><label>ISBN: </label>9061919274 (v.1) 9061919282 (v.2) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Underground construction.<br/>Underground areas.