APA (7th ed.) Citation

Walker, E. D., & Purnell, W. F. (1964). Understanding soils (Rev.). Univ. of Ill.

Chicago Style (17th ed.) Citation

Walker, Ernest D., and W. F. Purnell. Understanding Soils. Rev. Urbana: Univ. of Ill, 1964.

MLA (9th ed.) Citation

Walker, Ernest D., and W. F. Purnell. Understanding Soils. Rev. Univ. of Ill, 1964.