T. N. Singh. <br/><br/>
Equivalent material moddel study :  development of mine model / 
T. N. Singh and B. Singh 
 - Dhanbad :  Central Mining Research Station,  1967 
 - 26 p. :  ill. ;  21 cm. 
 - Reference CMRS M 21/40 .
<br/><br/><label>Dewey Class. No.: </label>622 (54)