De Defectu Oraculorum

Περὶ τῶν ἐκλελοιπότων Plutarch. Plutarchi Chaeronensis Moralia, Vol IΙI. Vernardakēs, Grēgorios N., editor. Leipzig: Teubner, 1891.

Why the Oracles Cease to Give Answers (eng) Plutarch. Plutarch's Morals, Vol. IV. Goodwin, William W., editor; Midgley, Robert translator. Boston: Little, Brown, and Company; Cambridge: Press of John Wilson and Son, 1874. The Obsolesence of Oracles (eng) Plutarch. Moralia, Vol. V. Babbitt, Frank Cole, translator. Cambridge, MA: Harvard University Press; London: William Heinemann Ltd., 1936 (printing).