Brennan 2001, s. 603, noting "the Romans obviously never came to terms with recognising the promagistracy as an actual office" after explaining that neither Livy nor Cicero use the titles "proconsul" or "propraetor". Brennan, T Corey (2001). The praetorship in the Roman republic. Oxford University Press. ISBN978-0-19-511460-7.
"Prorogation of imperium before the Hannibalic war". Latomus. ISSN0023-8856. Cf Livy 3.4.10.
Drogula, Fred K (2019). Cato the Younger: life and death at the end of the Roman republic. New York: Oxford University Press. s. 158. ISBN978-0190869021. OCLC1090168108.