APA (7th ed.) Citation

Riebel, J. P., & Roberts, D. R. (1957). Ten commandments for writing letters that get results. Printers' Ink Books.

Chicago Style (17th ed.) Citation

Riebel, John P., and Donald R. Roberts. Ten Commandments for Writing Letters That Get Results. Pleasantville, N.Y.: Printers' Ink Books, 1957.

MLA (9th ed.) Citation

Riebel, John P., and Donald R. Roberts. Ten Commandments for Writing Letters That Get Results. Printers' Ink Books, 1957.