M. Postle, Sir Joshua Reynolds: The Subject Pictures, Cambridge University Press, 1995, p. 200-6.
D. Mannings, Sir Joshua Reynolds: A complete catalogue of his paintings, New Haven and London, 2000, I, p. 572, no. 2175; II, p. 617, fig. 1709, as 'An accomplished replica of the prime version [Earl of Upper Ossory]... Although the handling in the present work is very reminiscent of Reynolds, a comparison with the prime original suggests that it is a Studio version'.