APA (7th ed.) Citation

Kanfer, S., & Marx, G. (2008). The essential Groucho: Writings by, for and about Groucho Marx. Penguin.

Chicago Style (17th ed.) Citation

Kanfer, Stefan, and Groucho Marx. The Essential Groucho: Writings by, for and About Groucho Marx. London: Penguin, 2008.

MLA (9th ed.) Citation

Kanfer, Stefan, and Groucho Marx. The Essential Groucho: Writings by, for and About Groucho Marx. Penguin, 2008.

Warning: These citations may not always be 100% accurate.