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.
Lacedaemon at the Hyacinthian. That they shall each erect a pillar, that at Lacedaemon near the statue of Apollo in the Amyclaeum, and that at Athens in the citadel, near
the statue of Minerva. That should the Lacedaemonians and Athenians choose to add to, or take away from, these terms of alliance, whatever they please so to do shall be consistent with the oaths of both parties.