Source: https://www.amazon.com/Richard-Diebenkorn-Beginnings-Scott-Shields/dp/0764979418/ref=pd_sbs_14_1?_encoding=UTF8&pd_rd_i=0764979418&pd_rd_r=ZZTX56S99DDC2A73YPVH&pd_rd_w=8NwWX&pd_rd_wg=G0tCa&psc=1&refRID=ZZTX56S99DDC2A73YPVH