Prendeville, J.: Explanatory catalogue of the proof-impressions of the antique gems possessed by the late Prince Poniatowski and now in the possession of John Tyrrell, Esq. (1841): 1143
Monson, (Lord)
Christie's, London: June 9, 1851, lot 83
Christie's, London: 27.06.1854; lot 147
Comments: Several of the Monson gems appear in the 1851 and the 1854 sale. They probably didn't sell the first time.