Jean-Luc Baroni Ltd. An Exhibition of Master Drawings and Paintings. Exh. cat., Carlton Hobbs LLC. New York, 2010, unpaginated, no. 33, ill. (color), states that it seems to be unconnected to any preparatory drawing or finished painting, and discusses it in the context of other bishop-saints depicted by the artist, in both large-scale works and small independent studies; finds it especially similar to two heads, both in private collections: a Saint Petronio (dated 1767) and a Saint Joseph.
Keith Christiansen in "Recent Acquisitions, A Selection: 2008–2010." Metropolitan Museum of Art Bulletin 68 (Fall 2010), p. 43, ill. (color).
Didier Rykner. "Acquisitions récentes du Metropolitan Museum: Annibale Carracci et Gaetano Gandolfi." Tribune de l'art. June 9, 2010, ill. (color) [http://www.latribunedelart.com/acquisitions-recentes-du-metropolitan-museum-annibale-carracci-et-gaetano-gandolfi-article002627.html], calls it possibly a study for the head of Saint Gilles in "The Holy Family Appearing to Saint Gilles" (church of Sant'Egidio, Bologna) of 1792.