I found a site last night that may be of some use. The "World Wide Arts Resources" website at
http://www.wwar.com has a section on artists of the past.
Go to the pull down menu where it says "Select a Database" (in the top right area of the screen). Then choose "Art History - Artists". Type in whatever artist you want to research and it shows you a list of his or her works by linking to the museum sites where they are held.
When I typed in Raeburn I got several examples, my favorite of which is the one I posted here.