Thorpe, E. (2009). Objective english (3rd. ed.). Pearson.
Chicago Style aipamenaThorpe, Edgar. Objective English. 3rd. ed. Chandigarh: Pearson, 2009.
MLA aipamenaThorpe, Edgar. Objective English. 3rd. ed. Pearson, 2009.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.