Code of practice for subsurface exploration by pits,trenches,drifts and shafts/1st rev. 

 - 1st rev.ed. 
 - New Delhi  Indian standards institution  1980 
<br/><br/><label>Subjects--Index Terms: </label>IS:4453-1980 
<br/><br/><label>Dewey Class. No.: </label>622.142:006.76