Cita APA (7th ed.)
Gurney Gene. (1970). Fact Book: Of the countries of the world. Crown Publ. Inc..
Cita Chicago (17th ed.)
Gurney Gene. Fact Book: Of the Countries of the World. New York: Crown Publ. Inc., 1970.
Cita MLA (9th ed.)
Gurney Gene. Fact Book: Of the Countries of the World. Crown Publ. Inc., 1970.
Atenció: Aquestes cites poden no estar 100% correctes.