APA način citiranja (7. izdanje)

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

Čikaški stil citiranja (17. izdanje)

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

MLA način citiranja (9. izdanje)

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