APA (7th ed.) Citation

Post, E. L. (1990). Emily Post on invitations and letters. Perennial Library.

Chicago Style (17th ed.) Citation

Post, Elizabeth L. Emily Post on Invitations and Letters. New York: Perennial Library, 1990.

MLA (9th ed.) Citation

Post, Elizabeth L. Emily Post on Invitations and Letters. Perennial Library, 1990.