Cresci, M. W. (1992). Complete book of model business letters. HCM.: ĐHTH.
Chicago Style aipamenaCresci, Martha W. Complete Book of Model Business Letters. HCM.: ĐHTH, 1992.
MLA aipamenaCresci, Martha W. Complete Book of Model Business Letters. HCM.: ĐHTH, 1992.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.