Walpole, Horace, 4th earl of Orford. The mysterious mother. A tragedy. Anon. London. Dodsley. 1781. vi, (1), 88 pp. sm. 8°.
*2575.20 Same, Dublin. Archer & J. 1791. x, 102 pp. Pls. Vignette. 8°. **G.3977.44
Same. (In Modern British drama. Vol. 2 pp. 549-570. London. 1811). 6570a.78.2 **G.3960.19.2 Same. (In his The Castle of Otranto. Pp. 149-277. London. 1925. **Q.2.28