Hubbard, R. L. (2007). Handbook for preclears. New Era Publications.
Chicago Style aipamenaHubbard, Ron L. Handbook for Preclears. Denmark: New Era Publications, 2007.
MLA aipamenaHubbard, Ron L. Handbook for Preclears. New Era Publications, 2007.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.