United States Geological Survey Bulletin ;
Woodruff, E G.
United States Geological Survey Bulletin ; no.581-A - Washington-US : United States Geological Survey Bulletin, 1914. - páginas 1-21 : IIustraciones blanco y negro - No. 581-A (1914) - United States Geological Survey Bulletin ; no.581-A . - United States Geological Survey. .
United States Geological Survey Bulletin ; no.581-A - Washington-US : United States Geological Survey Bulletin, 1914. - páginas 1-21 : IIustraciones blanco y negro - No. 581-A (1914) - United States Geological Survey Bulletin ; no.581-A . - United States Geological Survey. .