Lauschke, Georg (1884- )
Spencer, Arthur Coe (1871-1964) United States of America. Geological Survey.
Lupton, Charles Thomas (1878-1935) United States of America. Geological Survey.
Winchester, Dean Eddy (1883-1936) Hares, Charles Joseph (1881-?) Lloyd Russell E. Parks, E. M. United States of America. Geological Survey.
Capps, Stephen R. (1881-1949) United States of America. Geological Survey.
Shaw, Eugene Wesley (1881-1935) Matson, George Charlton (1873-?) Wegemann, Carroll Harvey (1879-?) United States of America. Geological Survey.
Marshall, Robert Bradford (1867-1949) United States of America. Geological Survey.
Eakin, Henry Miner (1883-1936) United States of America. Geological Survey.
Marshall, Robert Bradford (1867-1949) United States of America. Geological Survey.
Marshall, Robert Bradford (1867-1949) United States of America. Geological Survey.
Marshall, Robert Bradford (1867-1949) United States of America. Geological Survey.
Brooks, Alfred Hulse (1871-1924) United States of America. Geological Survey.
Marshall, Robert Bradford (1867-1949) United States of America. Geological Survey.
Deutsche Landwirtschafts-Gesellschaft
Butler, Bert Sylvenus (1877-1960) Heikes, Victor Conrad(1867-1948) United States of America. Geological Survey.
Jones, Edward L. United States of America. Geological Survey.
Hill, James Madison (1884-?) United States of America. Geological Survey.
Gannett, Samuell Stinson (1861-1939) United States of America. Geological Survey.
Jones, Edward L. United States of America. Geological Survey.
Ferguson, Henry Gardiner(1882-1966) United States of America. Geological Survey.
Hares, Charles Joseph (1881-?) United States of America. Geological Survey.
Brooks, Alfred Hulse (1871-1924) United States of America. Geological Survey.
Brooks, Alfred Hulse (1871-1924) United States of America. Geological Survey.