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.
On their way they came to Beroea and thence to Strepsa,[*](In Mygdonia, north of Therme.) and after an unsuccessful attempt upon this place proceeded overland to Potidaea with three thousand hoplites of their own and with many of their allies besides, and with six hundred Macedonian cavalry, who were under the command of Philip and Pausanias; and at the same time their ships, seventy in number, sailed along the coast.
And marching leisurely they arrived on the third day at Gigonus, and went into camp.