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.
But Demosthenes the Athenian, who happened to have remained in the neighbourhood of Naupactus after his retreat from Aetolia, got information of the expedition, and fearing for the town went and persuaded the Acarnanians, though with difficulty on account of his withdrawal from Leucas, to come to the aid of Naupactus.
And they sent with him on board the fleet[*](ie. the fleet of the Acarnanians themselves; the thirty Athenian ships, which Demosthenes had commanded, had returned to Athens (3.98.5), while those mentioned 3.105.3 did not come till later.) one thousand hoplites, who entered the place and saved it; for there was danger that they might not be able to hold out, since the walls were extensive and the defenders few in number.