C St J Yales. (1992). May I help you: A course for restaurant and bar staff. New York: Prentice-Hall.
Chicago Style aipamenaC St J Yales. May I Help You: A Course for Restaurant and Bar Staff. New York: Prentice-Hall, 1992.
MLA aipamenaC St J Yales. May I Help You: A Course for Restaurant and Bar Staff. New York: Prentice-Hall, 1992.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.