Hedrick, T. E. (1993). Applied research design: A practical guide.
Chicago Style aipamenaHedrick, Terry E. Applied Research Design: A Practical Guide. Sage Publications, New Delhi, 1993.
MLA aipamenaHedrick, Terry E. Applied Research Design: A Practical Guide. 1993.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.