Cita APA (7th ed.)
ebrary, Inc, Lewis, D. S., & Slater, W. (2010). World events 2009. ProQuest.
Cita Chicago (17th ed.)
ebrary, Inc, D. S. Lewis, i Wendy Slater. World Events 2009. Ann Arbor, Mich.: ProQuest, 2010.
Cita MLA (9th ed.)
ebrary, Inc, et al. World Events 2009. ProQuest, 2010.
Atenció: Aquestes cites poden no estar 100% correctes.