Thomson, A. J., & Martinet, A. V. Auxiliary verbs (8a ed.).
Chicago Style aipamenaThomson, A. J., and A. V. Martinet. Auxiliary Verbs. 8a ed.
MLA aipamenaThomson, A. J., and A. V. Martinet. Auxiliary Verbs. 8a ed.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.