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.
The Argives accepted this proposal at first, and the army of the Lacedaemonians returned home from Tegea. But not long after this, when there was now intercourse between them, the same men again brought it about that the Argives renounced the alliance with the Mantineans, Eleans, and Athenians and concluded a treaty and an alliance with the Lacedaemonians to this effect: