HORUS EDITIONS. (2002). THE ULTIMATE HOW IT WORKS ENCYCLOPEDIA. HORUS EDITIONS.
Cita Chicago (17th ed.)HORUS EDITIONS. THE ULTIMATE HOW IT WORKS ENCYCLOPEDIA. HORUS EDITIONS, 2002.
Cita MLA (9th ed.)HORUS EDITIONS. THE ULTIMATE HOW IT WORKS ENCYCLOPEDIA. HORUS EDITIONS, 2002.
Atenció: Aquestes cites poden no estar 100% correctes.