APA (7th ed.) Citation

Marx, G. (1967). The groucho letters: Letters from and to groucho marx. Ms. Rowan.

Chicago Style (17th ed.) Citation

Marx, Groucho. The Groucho Letters: Letters from and to Groucho Marx. New York: Ms. Rowan, 1967.

MLA (9th ed.) Citation

Marx, Groucho. The Groucho Letters: Letters from and to Groucho Marx. Ms. Rowan, 1967.