APA (7th ed.) Citation

Hawker, H. W., & Simmons, C. S. (1929). Soil survey of Willacy County, Texas. [U.S. Govt. Print. Off].

Chicago Style (17th ed.) Citation

Hawker, H. W., and C. S. Simmons. Soil Survey of Willacy County, Texas. Washington: [U.S. Govt. Print. Off], 1929.

MLA (9th ed.) Citation

Hawker, H. W., and C. S. Simmons. Soil Survey of Willacy County, Texas. [U.S. Govt. Print. Off], 1929.