Erich S. Gruen, The Last Generation of the Roman Republic (University of California Press, 1974, 1995), p. 525 online, noting that "one can do no more than guess" at the date.
"There are relatively few recorded instances of death sentences actually being carried out against Roman citizens during the Republican period," notes Kelly, History of Exile, p. 1 online.
Ronald Syme, "Rome and the Balkans, 80 BC–AD 14," in The Provincial at Rome (University of Exeter Press, 1999), p. 168 online.
