by W. H. Buckhannan, in charge ... [and others] ; United States Department of Agriculture in cooperation with the Oklahoma Agricultural Experiment Station
by H.P. Ulrich ... [and others] ; [United States Department of Agriculture, Agricultural Research Administration, Bureau of Plant Industry, Soils, and Agricultural Engineering in cooperation with the Purdue University Agricultural Experiment Station]
by John L. Retzer ... [and others] ; United States Department of Agriculture, Agricultural Research Administration, Bureau of Plant Industry, Soils and Agricultural Engineering in cooperation with the University of California Agricultural Experiment Station
by O.C. Rogers ... [and others] ; [United States Department of Agriculture, Bureau of Plant Industry, Soils, and Agricultural Engineering, Agricultural Research Administration in cooperation with the Purdue University Agricultural Experiment Station]
by Wilber Secor ... [and others] ; United States Department of Agriculture, Agricultural Research Administration, Bureau of Plant Industry, Soils, and Agricultural Engineering in cooperation with the Cornell University Agricultural Experiment Station