Duiker, W. J., & Spielvogel, J. J. (2004). World history (4th ed.). Thomson/Wadsworth.
Cita Chicago (17th ed.)Duiker, William J., i Jackson J. Spielvogel. World History. 4th ed. Belmont, CA: Thomson/Wadsworth, 2004.
Cita MLA (9th ed.)Duiker, William J., i Jackson J. Spielvogel. World History. 4th ed. Thomson/Wadsworth, 2004.
Atenció: Aquestes cites poden no estar 100% correctes.