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.
The Argives, having discovered it, advanced from Nemea, when it was now day, to their succour; and falling in with the forces of the Phliasians and Corinthians, killed a few of the former, but themselves had rather more killed by the latter.
And now the Boeotians, Megareans, and Sicyonians advanced, as they had been ordered, towards Nemea, and found the Argives no longer there; but they had gone down, on seing their property ravaged, and were forming for battle; while the Lacedaemonians also were preparing to meet them.