Cita APA (7th ed.)
Language Network: Grammar, Writing, Communication. McDougal Littel.
Cita Chicago (17th ed.)
Language Network: Grammar, Writing, Communication. Evanston, EUA: McDougal Littel.
Cita MLA (9th ed.)
Language Network: Grammar, Writing, Communication. McDougal Littel.
Atenció: Aquestes cites poden no estar 100% correctes.