↑ Bennett, Julian (1997). Trajan: Optimus Princeps: A Life and Times. New York & London: Routledge. m/s. 113–125.
↑ John W. Roberts, penyunting (2007). Pliny the Younger. The Oxford Dictionary of the Classical World. Oxford: Oxford University Press. ISBN9780192801463. Dicapai 24 March 2014. The tenth bk. of letters contains all of Pliny's correspondence with Trajan. [...] The provincial letters are the only such dossier surviving entire, and are a major source for understanding Roman provincial government. (subscription required)
↑ Cf. Pliny: A Self-Portrait in Letters, Intro. pp.10–16
