Jones, L., & Leo jones. (1986). Progress to Proficiency: Student is book. Cambridge University Press: Cambridge.
Chicago Style aipamenaJones, Leo, và Leo jones. Progress to Proficiency: Student Is Book. Cambridge University Press: Cambridge, 1986.
MLA aipamenaJones, Leo, và Leo jones. Progress to Proficiency: Student Is Book. Cambridge University Press: Cambridge, 1986.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.