The catalogue raisonné was presented as the author's doctoral dissertation for the University of Bonn in 2004. A digital copy of the entire dissertation can be downloaded in full or in parts as a pdf from the University of Bonn library. In addition to the catalogue, the publication includes a discussion of the artist's life, works, and critical reception. The chronological catalogue raisonné lists approximately 2,500 paintings, drawings, sculptures, and other works on paper.