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.
After this, the Greeks in Sicily continued to make war on each other by land without the co-operation of the Athenians.
At Pylus, in the mean time, the Athenians were still blockading the Lacedaemonians in the island, and the Peloponnesian forces on the continent remained where they were. But the watch was kept by the Athenians with great trouble, through want of both victuals and water;