Butler, Bert Sylvenus (1877-1960) Loughlin, Gerald Francis (1880-1946) United States of America. Geological Survey.
Butler, Bert Sylvenus (1877-1960) United States of America. Geological Survey.
Butler, Bert Sylvenus (1877-1960) Heikes, Victor Conrad(1867-1948) United States of America. Geological Survey.
Butler, Bert Sylvenus (1877-1960) Gale, Hoyt Stoddard (1876-1952) United States of America. Geological Survey.