Library of Congress
Authorities & Vocabularies
found: Stiftung Ludwig, 1976.
found: German Wikipedia WWW site, Nov. 29, 2010 (under Irene Ludwig: Irene Maria Therese Ludwig, née Monheim; b. June 17, 1927, Aachen; m. Peter Ludwig, 1951 (d. 1996); d. there Nov. 28, 2010; German art historian, art collector, and art patron)
found: Information from 678 converted Dec. 8, 2014 (maiden name Irene Monheim; married Peter Ludwig in 1951)