1930. Bushnell, T. M. (Thomas Mark),1889-1976,surveyor., Hendrickson, B. H. (Bertram Higbie),1892-surveyor, Kunkel, D. R. (David Roy),1901-surveyor., and Ulrich, H. P. (Herbert Paul),1904-surveyor. Shows soil types classification by colors and symbols. 'Field Operations, Bureau of Chemistry and Soils, 1930.' 'Lith Eastern Offset Inc., Balto.' ... The Bureau.