APA (7th ed.) Citation

Friedman, T. L. (2006). The world is flat: The globalized world in the twenty-first century. Penguin Books.

Chicago Style (17th ed.) Citation

Friedman, Thomas L. The World Is Flat: The Globalized World in the Twenty-first Century. London: Penguin Books, 2006.

MLA (8th ed.) Citation

Friedman, Thomas L. The World Is Flat: The Globalized World in the Twenty-first Century. Penguin Books, 2006.