Cita APA (7th ed.)
Friedman, T. L. (2006). The world is flat: The globalized world in the twenty-fist century. Penguin Books.
Cita Chicago (17th ed.)
Friedman, Thomas L. The World Is Flat: The Globalized World in the Twenty-fist Century. 2006: Penguin Books, 2006.
Cita MLA (9th ed.)
Friedman, Thomas L. The World Is Flat: The Globalized World in the Twenty-fist Century. Penguin Books, 2006.
Atenció: Aquestes cites poden no estar 100% correctes.