Robuta

https://www.christies.com/zh-cn/lot/lot-5143456 Robert Ryman (b. 1930) , Series #33 (White) | Christie's robert ryman 1930 series 33 white christie https://nla.gov.au/nla.obj-348498884/view?partId=nla.obj-348514236 Third series, No. 31 (1 March 1930) third series no 31 march 1930