The histories.

MLA

Polybius, et al. The Histories. Rev. ed. Cambridge: Harvard university press, 2010.

APA

Polybius, P., Paton, W. R, Walbank, F. William, Habicht, C., & Olson, S. Douglas. (2010). The histories. Rev. ed. Cambridge: Harvard university press.

Chicago

Polybius., Frank William Walbank, and Christian Habicht. The Histories. Translated by William R Paton. Edited by S. Douglas Olson. Rev. ed. Cambridge: Harvard university press, 2010.