Cita APA

(2001). The World book encyclopedia: W-X-Y-Z V.21. World book, Inc.

Chicago Style Citation

The World Book Encyclopedia: W-X-Y-Z V.21. World book, Inc, 2001.

Cita MLA

The World Book Encyclopedia: W-X-Y-Z V.21. World book, Inc, 2001.

Atenció: Aquestes cites poden no estar 100% correctes.