Quantum redactiones paginae "Annus quattuor imperatorum" differant

== Bibliographia ==
* Rhiannon Ash, ''Ordering anarchy: armies and leaders in Tacitus' Histories''. Londinii: Duckworth, 1999. ISBN 0715628003
* Arther Ferrill, "Otho, Vitellius, and the Propaganda of Vespasian" in ''Classical Journal'' vol. 60 (1965) pp. 267-269
* Egon Flaig, ''Den Kaiser herausfordern. Die Usurpation im Römischen Reich''. Francofurti ad Moenum, 1992. ISBN 3-593-34639-7
* P. A. L. Greenhalgh, ''The year of four emperors''. 1975