Cita APA

Friedman, T. L. (2005). The world is flat: A brief history of the twenty-first century. London: Penguin Books.

Citación estilo Chicago

Friedman, Thomas L. The World Is Flat: A Brief History of the Twenty-first Century. London: Penguin Books, 2005.

Cita MLA

Friedman, Thomas L. The World Is Flat: A Brief History of the Twenty-first Century. London: Penguin Books, 2005.