• Polybius, Histories Books 1 and 3 — For the Truceless War and the causes of the Second Punic War respectively. Available via Perseus Digital Library.
• Dexter Hoyos, Truceless War: Carthage's Fight for Survival, 241 to 237 BC (2007) — The fullest modern account of the mercenary revolt.
• Dexter Hoyos, Hannibal's Dynasty: Power and Politics in the Western Mediterranean, 247-183 BC (2003) — Essential for the Barcid political context.
• Eve MacDonald, Hannibal: A Hellenistic Life (2015) — Places the Barcids in the Hellenistic context rather than reading them as proto-Romans.
• Richard Miles, Carthage Must Be Destroyed (2010) — Good on the Barcid project from the Carthaginian perspective.
• Livy, Ab Urbe Condita, Book 21 — The Roman account of Hannibal's rise and the war's outbreak. Vivid, often beautiful, and not always reliable. Polybius is the corrective.

The oath story comes from Polybius, where he reports that Hannibal told it at the court of Antiochus III. Livy's version is more dramatic and shifts the emphasis from political commitment to personal hatred. The modern scholarly discussion of what the oath means and whether it happened is nicely summarized in Dexter Hoyos's biography Hannibal: Rome's Greatest Enemy (2008), which takes a careful line on both questions. Eve MacDonald's Hannibal: A Hellenistic Life (2015) is the best recent treatment of Hannibal as a product of the Hellenistic world rather than simply a military genius operating in a Roman narrative frame.