One interesting source of information is:
<Salt Mines and Castles> by Thomas Carr Howe, Jr. The Bobbs-Merrill Co.,
Indianapolis.  1945.
 
Subtitle: The Discovery and Restitution of Looted European Art.
 
There are numerous illustration, as well as an appendix listing paintings
transferred from Germany to the National Gallery, and copies of
correspondence protesting this action.
 
Jack C. Thompson
Thompson Conservation Lab
Portland, OR
 
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