Fowler, W. S., Pidcock, J., & Yorkey, R. C. Incentive themes. Book 4, teacher´s edition.
Chicago Style aipamenaFowler, W. S., J. Pidcock, and Richard C. Yorkey. Incentive Themes. Book 4, Teacher´s Edition.
MLA aipamenaFowler, W. S., et al. Incentive Themes. Book 4, Teacher´s Edition.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.