Wheler, A. S. <br/><br/>
Bulletin of the Institution of Mining and Metallurgy,  ;   No. 137 

 - Londres-XXK :   The Institution of Mining and Metallurgy,   1916. 
 - p. 1-14 :   maps., il. 
 - Irregular 
 - No. 137(Feb.1916) 
 - Bulletin of the Institution of Mining and Metallurgy,  ;   No. 137 .
 - Reino Unido.   The Institution of Mining and Metallurgy,. .