APA (7th ed.) Citation

Butterfiel, W. (1964). Effective personal letters (2nd rev.). Prentice Hall.

Chicago Style (17th ed.) Citation

Butterfiel, W. Effective Personal Letters. 2nd rev. Englewood Cliffs: Prentice Hall, 1964.

MLA (9th ed.) Citation

Butterfiel, W. Effective Personal Letters. 2nd rev. Prentice Hall, 1964.