APA aipamena

O'Connell, S. (1989). Focus on proficiency. Collings: London and Galasgow.

Chicago Style aipamena

O'Connell, Sue. Focus On Proficiency. Collings: London and Galasgow, 1989.

MLA aipamena

O'Connell, Sue. Focus On Proficiency. Collings: London and Galasgow, 1989.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.