Gairns, R. (2009). Oxford word skills. Vermilion.
Cita Chicago (17th ed.)Gairns, Ruth. Oxford Word Skills. London: Vermilion, 2009.
Cita MLA (9th ed.)Gairns, Ruth. Oxford Word Skills. Vermilion, 2009.
Atenció: Aquestes cites poden no estar 100% correctes.