Grolier International. Grolier academic encyclopedia: Vol :3. Grolier International.
Cita Chicago (17th ed.)Grolier International. Grolier Academic Encyclopedia: Vol :3. USA: Grolier International.
Cita MLA (9th ed.)Grolier International. Grolier Academic Encyclopedia: Vol :3. Grolier International.
Atenció: Aquestes cites poden no estar 100% correctes.