"Let us stop for a while before that superb edifice of the Doric order, which now presents itself to view. This is called the Propylaea or vestibules of the citadel. Pericles had them built of marble, after the designs and under the inspection of the architect Mnesicles. They were begun under the archonship of Euthymenes, but not completed till five years after; and are said to have cost two thousand and twelve talents, an exorbitant sum, exceeding the whole annual revenue of the republic." Anacharsis Vol. 2, pp. 215-216
Barthelemy, Jean Jacques. The Travels of Anacharsis the Younger in Greece. 8 vols. London: G. Woodfall, 1806.
Fowler, Harold North, James Rignall Wheeler, and Gorham Phillips Stevens. A Handbook of Greek Archaeology. New York, Cincinnati, Chicago: American Book Company, 1909.
Verrall, Margaret de G. and Jane E. Harrison. Mythology and Monuments of Ancient Athens. London and New York: Macmillan and Co., 1890.