In 1974, conceptual artist Hans Haacke created "Manet-PROJEKT '74," which traced the ownership history of Édouard Manet's "Bunch of Asparagus". This project revealed how the painting passed from a Jewish art collector to Hermann Josef Abs, a financial advisor to Hitler. Haacke's work aimed to highlight the political and social implications of art ownership. The project was rejected by the Wallraf-Richartz Museum in Cologne due to its connection to Abs.