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.
on which account he hurried or the more, wishing to surprise the people of Amphipolis, except those who were to betray it.
For there were residing in it some Argilians, (this people are a colony from Andros,) and some others, who were carrying on this intrigue together; some at the suggestion of Perdiccas, others at that of the Chalcidians.