United States Department of Agriculture, Natural Resources Conservation Service ; in cooperation with the Oklahoma Agricultural Experiment Station and the Oklahoma Conservation Commission
by W. H. Buckhannan, in charge ... [and others] ; United States Department of Agriculture in cooperation with the Oklahoma Agricultural Experiment Station
United States Department of Agriculture, Soil Conservation Service in cooperation with the Oklahoma Agricultural Experiment Station ; [by Carl F. Fisher ... and others]
United States Department of Agriculture, Soil Conservation Service in cooperation with Oklahoma Agricultural Experiment Station ; [by Harvey Oakes ... and others ; correlation by James Thorp]