Robinson, W. O. (William Orrin), b. 1884, McCaughey, W. J. (William John), 1882-1962, United States. Dept. of Agriculture, United States. Bureau of Soils, United States. Government Printing Office · Washington : Govt. Print. Off. · leaf 3
Issued May 1, 1911. U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF SOILS— BULLETIN NO. 79. MILTON WHITNEY, Chief. THE GOLOR OF SOILS. BY W. O. ROBINSON, Scientist in Soil Laboratory Investigations, and W. J. McCAUGHEY, Scientist in Soil Laboratory Investigations. … WASHINGTON: GOVERNMENT PRINTING OFFICE. 1911.
Soils Color · Soils Composition
Internet Archive · U.S. Department of Agriculture, National Agricultural Library · Public domain (published before 1931). Free to use for anything.
