Ponrajaha, A.J.P. <br/><br/>
Tunnelling in rocks 

 - Engineering Geology Division, Department of Irrigation  Colombo 07  1999 
 - 100 p.  Fig., Table, Chart 
<br/><br/><label>Nat. Bib. No.: </label>6868 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Engineering
<br/><br/><label>Universal Decimal Class. No.: </label>624.19  / PON