History of the Peloponnesian War
Thucydides
Thucydides. The history of the Peloponnesian War, Volume 1-2. Dale, Henry, translator. London: Heinemann and Henry G. Bohn, 1851-1852.
With reference to the ten days' truces also, which had been made with each other by the Athenians and Boeotians not long after the conclusion of the fifty years' treaty, the Corinthians desired the Boeotians to accompany them to Athens, and obtain the same for them also, on the same footing as the Boeotians; and in case of the Athenians not acceding to this, then to renounce the suspension of arms, and in future to make no truce without being joined by them. On the Corinthians preferring these requests, the Boeotians desired them to desist on the subject of the Argive alliance:
they went with them, however, to Athens, but did not obtain the ten days' truce; as the Athenians answered, that they were already in treaty with the Corinthians, inasmuch as they were allies of the Lacedaemonians.