Duiker, W. J., & Spielvogel, J. J. (2016). World history (Eighth edition.). Cengage Learning.
Cita Chicago (17th ed.)Duiker, William J., i Jackson J. Spielvogel. World History. Eighth edition. Australia: Cengage Learning, 2016.
Cita MLA (9th ed.)Duiker, William J., i Jackson J. Spielvogel. World History. Eighth edition. Cengage Learning, 2016.
Atenció: Aquestes cites poden no estar 100% correctes.