APA (7th ed.) Citation

National Fertilizer Association (1925-1955), Smalley, H. R., Engle, R. H., & Willett, H. (1939). American fertilizer practices (second survey): A report relating to the use of commercial plant food, presenting information obtained by a survey among 32,000 farmers in 35 states. The Association.

Chicago Style (17th ed.) Citation

National Fertilizer Association (1925-1955), Harold Ryland Smalley, Robert H. Engle, and Herbert Willett. American Fertilizer Practices (second Survey): A Report Relating to the Use of Commercial Plant Food, Presenting Information Obtained by a Survey Among 32,000 Farmers in 35 States. [Washington]: The Association, 1939.

MLA (9th ed.) Citation

National Fertilizer Association (1925-1955), et al. American Fertilizer Practices (second Survey): A Report Relating to the Use of Commercial Plant Food, Presenting Information Obtained by a Survey Among 32,000 Farmers in 35 States. The Association, 1939.