Cita APA (7th ed.)
(1994). The world book encyclopedia: Vol.9 (ed.). World book, Inc..
Cita Chicago (17th ed.)
The World Book Encyclopedia: Vol.9. ed. Chicago: World book, Inc., 1994.
Cita MLA (9th ed.)
The World Book Encyclopedia: Vol.9. ed. World book, Inc., 1994.
Atenció: Aquestes cites poden no estar 100% correctes.