APA (7th ed.) Zitazioa
Hearn, P. (1979). Successful negotiation of commercial contracts. Oyez.
Chicago Style (17th ed.) Zitazioa
Hearn, Patrick. Successful Negotiation of Commercial Contracts. London: Oyez, 1979.
MLA (9th ed.) Zitazioa
Hearn, Patrick. Successful Negotiation of Commercial Contracts. Oyez, 1979.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.