Covers
Martin Hopfengart is a German author living in Denmark. His novel "49 - so eine Art Roman" was released as an audiobook on Audible and other platforms. The cover artwork is influenced by M.C. Escher and develops the Penrose triangle / Escher tribar into the number "49", because the story takes place over seven weeks (49 days).
Author's page at Facebook https://www.facebook.com/martin.hopfengart.10.