BARNES C. (1988). PROFESSIONAL EXCELLENCE FOR SECRETARIES. CRISP PUBLICATION.
Chicago Style aipamenaBARNES C. PROFESSIONAL EXCELLENCE FOR SECRETARIES. CALIFORNIA: CRISP PUBLICATION, 1988.
MLA aipamenaBARNES C. PROFESSIONAL EXCELLENCE FOR SECRETARIES. CRISP PUBLICATION, 1988.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.