Welch, C. D., Grey, C., & Pennington, D. (1980). How to get your soil tested. Texas Agricultural Extension Service, Texas A & M University System.
Chicago Style (17th ed.) CitationWelch, C. D., Carl Grey, and Dale Pennington. How to Get Your Soil Tested. College Station: Texas Agricultural Extension Service, Texas A & M University System, 1980.
MLA (9th ed.) CitationWelch, C. D., et al. How to Get Your Soil Tested. Texas Agricultural Extension Service, Texas A & M University System, 1980.
Warning: These citations may not always be 100% accurate.