Ordish, T. Fairman, “English Folk-Drama,” in Folk-lore, iv. (1893).
Orelli, J. C., Inscriptionum Latinarum selectarum amplissima collectio. Zürich, 1828-1856.
Orient und Occident.
Origen, Commentarium in Joannem II., in Migne's Patrologia Graeca, xiv.
Contra Celsum, in Migne's Patrologia Graeca, xi.
In Jeremiam Hom. XV. 4, in Migne's Patrologia Graeca, xiii.
Selecta in Ezechielem, in Migne's Patrologia Graeca, xiii.
Original-Mittheilungen aus der ethnologischen Abtheilung der königlichen Museen zu Berlin.
Orphica. Ed. E. Abel. Leipsic and Prague, 1885.
Orphica. Ed. G. Hermann. Leipsic, 1805.