WG
William H. Gerdts
William Henry Gerdts Jr. was an American art historian and professor of Art History at the CUNY Graduate Center. Gerdts was the author of over twenty-five books on American art. An expert in American Impressionism, he was also well known for his work on nineteenth-century American still life painting.
Excerpt from Wikipedia, available under CC BY-SA 4.0.
Books

Sargent's Venice
2006
ISBN 9780300117172