Picture titled (sigma 3)

I've reason to believe this picture is by sigmar polke,I once seen it in a art monthly magazine where 4 pages were dedicated to the artist of the picture the picture title is sigma 3 ,I know art monthly done a piece in March 95 ,issue 3/184 also issue 34/243 February 2001 even though I thought the picture was in 98/99 issues. Can anyone help ,also how do I download a photo so you can view it ,your help would be really appreciated,thankyou andy the picture is from 1967 .