Maxwell-Lefroy, E. <br/><br/>
Bulletin of the Institution of Mining and Metallurgy,  ;   No. 141 

 - Londres-XXK :   The Institution of Mining and Metallurgy,   1916. 
 - p. 1 
 - Irregular 
 - No. 141(Jun.1916) 
 - Bulletin of the Institution of Mining and Metallurgy,  ;   No. 141 .
 - Reino Unido.   The Institution of Mining and Metallurgy,. .