Merriam C., Jhon. <br/><br/>
Bulletin of the Departament of Geology ;   no. 6 

 - California-US :   Universuty of California Pres Serkeley,   1915. 
 - páginas 49-58 
 - Irregular 
 - Vol. 9, no. 4(Nov. 1915) 
 - Bulletin of the Departament of Geology ;   no. 6 .
 - Unioversity of California Publications. .