Alexander, John W. <br/><br/>
Population density maps of the united states techniques and patterns.   

 - New York-US :   Geografical record,   1943. 
 - páginas 457-466 :   Ilustraciones blanco y negro 
 - Irregular 
 - Vol. XXXIII, no. 3(Jul. 1943) 
 - The Geographical Review ;   no. 3 .
 - The Geographical Review. .