Schulman, Edmundo. <br/><br/>
Runoff histories in tree rings of the pacific slope. 

 - New York-US :   Geografical record,   1945. 
 - páginas 58-73 :   Ilustraciones blanco y negro 
 - Irregular 
 - Vol. XXXIV, no. 1(Jan. 1945) 
 - The Geographical Review ;   no. 1 .
 - The Geographical Review. .