Cita APA (7th ed.)

Low, O. (1975). A new certificate of proficiency English course whit practice and test papers (3a. ed.). Edward Arnold.

Cita Chicago (17th ed.)

Low, Ona. A New Certificate of Proficiency English Course Whit Practice and Test Papers. 3a. ed. Londres: Edward Arnold, 1975.

Cita MLA (9th ed.)

Low, Ona. A New Certificate of Proficiency English Course Whit Practice and Test Papers. 3a. ed. Edward Arnold, 1975.