Dantaon: Pagkakaiba sa mga binago

* [ftp://ftp.loc.gov/pub/reference.guides/battle.centuries.txt''The Battle of the Centuries''], Ruth Freitag, [[U.S. Government Printing Office]]. Available from the Superintendent of Documents, P.O. Box 371954, Pittsburgh, PA 15250- 7954. Cite stock no. 030-001-00153-9. Hinango noong 3 Marso 2019. (sa Ingles)