Emmatt, s. (2013). 10 Billion. Penguin Books.
Cita Chicago (17th ed.)Emmatt, stephen. 10 Billion. London: Penguin Books, 2013.
Cita MLA (9th ed.)Emmatt, stephen. 10 Billion. Penguin Books, 2013.
Atenció: Aquestes cites poden no estar 100% correctes.