Auctioned at Grisebach Berlin

https://www.invaluable.com/auction-lot/herman-van-den-boom-ohne-titel-1977.-vintage.-1521-c-zmdckfr95q?fb_action_ids=10202871645064006&fb_action_types=og.likes&fb_ref=.VHe0Hlk7Vic.like&fb_source=other_multiline&action_object_map=%5B670850776368420%5D&action_type_map=%5B%22og.likes%22%5D&action_ref_map=%5B%22.VHe0Hlk7Vic.like%22%5D#