FORSYTH PATRICK. (1999). MARKETING PROFESSIONAL SERVICES (2ND.). KOGAN PAGE.
Chicago Style aipamenaFORSYTH PATRICK. MARKETING PROFESSIONAL SERVICES. 2ND. LONDON: KOGAN PAGE, 1999.
MLA aipamenaFORSYTH PATRICK. MARKETING PROFESSIONAL SERVICES. 2ND. KOGAN PAGE, 1999.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.