https://www.theartnewspaper.com/preview/east-german-arseholes-are-reappraised
Unknown or Unreal? The Shadow Over Some Russian Avant-Garde Art
https://www.nytimes.com/2018/04/06/arts/design/russian-avant-garde-art-forgery-disputes.html
Mondrian Heirs Stake Claim to Four Paintings in German Museum
https://www.nytimes.com/2018/03/04/arts/mondrians-heirs-stake-claim-to-four-paintings-in-a-german-museum.html
After 26 years, Munich settles in Nazi-looted Klee case
https://www.nytimes.com/2017/07/26/arts/design/after-26-years-munich-settles-case-over-a-klee-looted-by-nazis.html
German Collectors Confront Past – New York Times, March 14
Do I have Nazi-looted art? German collectors seek answers