[by H.H. Perry ... and others] ; United States Department of Agriculture, Soil Conservation Service in cooperation with the Virginia Agricultural Experiment Station and the Tennessee Valley Authority
[by B.L. Matzek ... and others] ; United States Department of Agriculture, Soil Conservation Service, in cooperation with the Tennessee Agricultural Experiment Station and the Tennessee Valley Authority
[by Robert Wildermuth ... and others] ; United States Department of Agriculture, Soil Conservation Service in cooperation with the Tennessee Agricultural Experiment Station and the Tennessee Valley Authority