Roman infantry tactics (English Wikipedia)

Lt. Col. S.G. Brady, The Military Affairs of Ancient Rome and Roman Art of War in Caesar's Time, The Military Service Publishing Company: 1947, url: http://www.digitalattic.org/home/war/romanarmy/ Archived 2013-09-09 at the Wayback Machine
Lt. Col. S.G. Brady, The Military Affairs of Ancient Rome and Roman Art of War in Caesar's Time, The Military Service Publishing Company: 1947 – url: http://www.digitalattic.org/home/war/romanarmy/ Archived 2013-09-09 at the Wayback Machine

etrusia.co.uk

Gaius Julius Caesar, Commentaries on the Gallic War, translated by W.A. McDevitte and W.S. Bohn. New York: Harper & Brothers, 1869. url: http://www.forumromanum.org/literature/caesar/gallic_e4.html#32

"Chariots: Warfare with Attitude". Archived from the original on 2006-12-10. Retrieved 2006-12-01.

Tacitus, Annals – Book II – "War with the Germans", THE REIGN OF TIBERIUS, OUT OF THE FIRST SIX ANNALS OF TACITUS; WITH HIS ACCOUNT OF GERMANY, AND LIFE OF AGRICOLA, TRANSLATED BY THOMAS GORDON, 1917. url: https://www.gutenberg.org/dirs/etext05/7rtib10.txt
Caesar's Commentaries (THE WAR IN GAUL – THE CIVIL WAR) English translation by W. A. MACDEVITT, introduction by THOMAS DE QUINCEY (1915) – At Gutenberg Project

Marcellinus, Ammianus, The Later Roman Empire, translated by Hamilton, W. (Penguin, 1987). See also Chris Cornuelle, An Overview of the Sassanian Persian Military, (n.d.) retrieved from May 2008 from Iran Chamber Society http://www.iranchamber.com/history/articles/overview_sassanian_persian_military2.php

"Military Training". 18 December 2021. Archived from the original on 1 September 2015. Retrieved 29 September 2015.

"Resource Tactics", Victori: The Roman Military Strategy and Tactics. http://romanmilitary.net/strategy/resource^{[unreliable source]}

See Polybius, The Histories for original commentary, The Histories or The Rise of the Roman Empire by Polybius: ** At Perseus Project: English & Greek version

"Military Training". 18 December 2021. Archived from the original on 1 September 2015. Retrieved 29 September 2015.
Lt. Col. S.G. Brady, The Military Affairs of Ancient Rome and Roman Art of War in Caesar's Time, The Military Service Publishing Company: 1947, url: http://www.digitalattic.org/home/war/romanarmy/ Archived 2013-09-09 at the Wayback Machine
Lt. Col. S.G. Brady, The Military Affairs of Ancient Rome and Roman Art of War in Caesar's Time, The Military Service Publishing Company: 1947 – url: http://www.digitalattic.org/home/war/romanarmy/ Archived 2013-09-09 at the Wayback Machine
"Chariots: Warfare with Attitude". Archived from the original on 2006-12-10. Retrieved 2006-12-01.
The Fifteen Decisive Battles Of The World Archived 2007-10-08 at the Wayback Machine: From Marathon To Waterloo by Sir Edward Creasy, M.A., 1851
"History of Rome: The Spanish Wars, by Appian, circa 165 A.D." Archived from the original on 2015-11-19. Retrieved 2020-03-26.