by William T. Carter ... [and others] ; United States Department of Agriculture, Bureau of Chemistry and Soils ; in cooperation with the Texas Agricultural Experiment Station
by M.J. Edwards ... [and others] ; United States Department of Agriculture, Bureau of Chemistry and Soils in cooperation with the Alabama Department of Agriculture and Industries
by Robert Wildermuth ... [and others] ; United States Department of Agriculture, Bureau of Chemistry and Soils in cooperation with the Washington Agricultural Experiment Station and Washington State Planning Council
by E.A. Nieschmidt ... [and others] ; United States Department of Agriculture, Bureau of Chemistry and Soils, in cooperation with the University of Nebraska State Soil Survey, Department of the Conservation and Survey Division
by James Thorp ... [and others] ; United States Department of Agriculture, Bureau of Chemistry and Soils, in cooperation with the University of Wyoming Agricultural Experiment Station
by E. J. Carpenter ... [and others] ; United States Department of Agriculture, Bureau of Chemistry and Soils ; in cooperation with the University of Wyoming Agricultural Experiment Station
by R.T. Avon Burke ... [and others] ; United States Department of Agriculture, Bureau of Chemistry and Soils ; in cooperation with the Pennsylvania State College School of Agriculture and Experiment Station
By C. S. Simmons ... [and others], United States Department of Agriculture, Bureau of Chemistry and Soils ; in cooperation with the Purdue University Agricultural Experiment Station