Cita APA (7th ed.)

Williams, A. (2012). Vocabulary for IELTS. HarperCollins Publishers.

Cita Chicago (17th ed.)

Williams, Anneli. Vocabulary for IELTS. London: HarperCollins Publishers, 2012.

Cita MLA (9th ed.)

Williams, Anneli. Vocabulary for IELTS. HarperCollins Publishers, 2012.