Greece
Aristotle. Politics. Translated by Benjamin Jowett. Oxford: Clarendon Press, 1885.
Greenridge, A. H. J. A Handbook of Greek Constitutional History. New York: MacMillan Co., 1896.
Rome
Polybius. Histories. Translated by Evelyn S. Shuckburgh. New York: MacMillan and Co., esp. bk. VI.
Lintott, Andrew. The Constitution of the Roman Republic. New York: Clarendon Press, 1999.
England
Locke, John. Second Treatise on Government. London: 1689, esp. chap. 12.
Montesquieu, Charles de Secondat, baron de. The Spirit of the Laws. Geneva, Switzerland: 1748, esp chap. 6 of bk. 11.
America
Wood, Gordon S. The Creation of the American Republic, 1776-1787. Chapel Hill, NC: University of North Carolina Press, 1969.
Gordon, Scott. Controlling the State: Constitutionalism from Ancient Athens to Today. Cambridge, MA: Harvard University Press, 1999.