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.
When Gylippus thought it a favourable opportunity, he commenced the attack; and, having closed in battle, they fought in the space between the works, where the cavalry of the Syracusans was of no use.