Berry, L. L. (1991). Marketing services: Competing through quality. Free Press.
Chicago Style aipamenaBerry, Leonard L. Marketing Services: Competing Through Quality. New York: Free Press, 1991.
MLA aipamenaBerry, Leonard L. Marketing Services: Competing Through Quality. Free Press, 1991.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.