[by Ralph C. Cole ... and others] ; United States Department of Agriculture, Soil Conservation Service in cooperation with the University of California Agricultural Experiment Station
[by R.A. Gardner ... and others] ; United States Department of Agriculture, Soil Conservation Service in cooperation with the California Agricultural Experiment Station
by Ralph C. Cole ... [and others] ; United States Department of Agriculture, Bureau of Plant Industry, Soils, and Agricultural Engineering and Soil Conservation Service in cooperation with the University of California Agricultural Experiment Station
[by Frank F. Harradine ... and others] ; United States Department of Agriculture, Soil Conservation Service in cooperation with the University of California Agricultural Experiment Station