United Press International. (1992). UPI stylebook: The authoritative handbook for writers, editors & news directors (Third edition.). National Textbook Company, a division of NTC Publishing Group.
Cita Chicago (17th ed.)United Press International. UPI Stylebook: The Authoritative Handbook for Writers, Editors & News Directors. Third edition. Lincolnwood, Illinois: National Textbook Company, a division of NTC Publishing Group, 1992.
Cita MLA (9th ed.)United Press International. UPI Stylebook: The Authoritative Handbook for Writers, Editors & News Directors. Third edition. National Textbook Company, a division of NTC Publishing Group, 1992.
Atenció: Aquestes cites poden no estar 100% correctes.