Hill, L. (1970). Elementary refresher course. Oxford University Pr.
Cita Chicago (17th ed.)Hill, L.A. Elementary Refresher Course. London: Oxford University Pr, 1970.
Cita MLA (9th ed.)Hill, L.A. Elementary Refresher Course. Oxford University Pr, 1970.
Atenció: Aquestes cites poden no estar 100% correctes.