Indian Standards Institution <br/><br/>
Indian standard code of practice for exploration by pits, trenches, drifts and shafts  sub-surface exploration sectional committee, BDC 49 

 - Indian Standards Institution, New Delhi  1968 
 - 15 
<br/><br/><label>Dewey Class. No.: </label>IS:4453-1967 624.15 I.S.I.