History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
"For renewal of the oath the Athenians shall go to Elis, to Mantinea, and to Argos, thirty days before the Olympic games; and the Argives, Eleans, and Mantineans shall go to Athens ten days before the great Panathenaea. 11.
"The stipulations respecting the treaty, the oaths, and the alliance shall be inscribed on a stone column, by the Athenians on the Acropolis,[*](A fragment of the official document recording this treaty was found by the Archaeological Society at Athens in the spring of 1877 upon a marble slab on the southern slope of the Acropolis. The text of the inscription has been restored by Kirchhoff, Schöne, Foucart, and Stahl in substantial agreement.) by the Argives in the market-place, in the temple of Apollo, by the Mantineans in the market-place, in the temple of Zeus; and a brazen pillar shall be set up by them jointly at the Olympic games of this year. 12.
“If it shall seem advisable to these states to add anything further to these agreements, whatever shall seem good to all the states in joint deliberation shall be binding.”