Sargent, R.H. <br/><br/>
Aerial photographic surveys in sputheastern Alaska. 

 - Washington-US :   Departament of the Interior,   1929. 
 - páginas 143-160 
 - Irregular 
 - No. 797 (1929) 
 - Geological Survet. Bulletin ;   no. 797 .
 - United States Goverment Printing Office. .
<br/><br/> Separata.