Harrison, I. (2004). The book of inventions: How'd they come up with that. National Geographic.
Cita Chicago (17th ed.)Harrison, Ian. The Book of Inventions: How'd They Come Up with That. Washington, D.C: National Geographic, 2004.
Cita MLA (9th ed.)Harrison, Ian. The Book of Inventions: How'd They Come Up with That. National Geographic, 2004.
Atenció: Aquestes cites poden no estar 100% correctes.