He is particularly known as a scholar of the Italian baroque and Salvator Rosa, with expertise on the 17th century, including Guercino and Caravaggio.
He received a prize for his work studying the links between the English and Italian art in 1600–1700.
He won the Fulbright prize and in London he started a prolific relation with Denis Mahon.
In the early 1960s, in collaboration with Mahon, he authenticated two Caravaggio paintings in American museums: “Martha and Mary Magdalene” (Detroit Institute of Arts) and “The Crucifixion of Saint Andrew” (Cleveland Museum of Art).
Includes biographical information and list of archival holdings.