Letter dated 10.2.1843 from J.C. Donnellan to Thorvaldsen.
Else Kai Sass: Thorvaldsens Portrætbuster, Copenhagen 1963-65, Vol. II, p. 292-296; Vol. III, p. 100 (kat. nr. 162) and p. 108 (suggests that it may be a portrait of John O’Brien of Fitzwilliam Square, Dublin. The year of his birth is not known; died before May 1830).