Lucan. De Bello Civili, a.k.a Pharsalia.

Plutarch. The Lives of the Noble Grecians and Romans. Trans. Thomas North (1595). 'Julius Caesar' and 'Pompey'.

REFERENCE : Robert Kean Turner, ed. 'The False One.' The Dramatic Works in the Beaumont and Fletcher Canon, gen. ed. Fredson Bowers. 10 vols. Cambridge: Cambridge University Press, 1966-96. Vol. 8.115-16.