This image is by Roy Lichtenstein and can be found in the best image database ever, the Collection Database of The Metropolitan Museum of Art. This database is well organized and easy to search and careful attention has been paid to the information that accompanies each piece. To top it off, there are explanations of how to search, use keywords and interpret captions.
In addition, there is a huge list of other image databases available online so if you are like me and particularly entranced by the handling of visual resources in digital collections you have a lot to consider.
The Metropolitan Museum of Art has always made me very happy. Go art!