Andy Warhol, Self-Portrait, 1986, Acrylic paint and screenprint on canvas, Tate, London. https://dartabase.art/cite/tate/T07146

Sigmar Polke, [Untitled], 1983, Gouache on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/35327

Sigmar Polke, o.T. COLOR TEST, BLUE (o.T. FARBPROBE, BLAU), 1984, Synthetic polymer paint on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/33178

Sigmar Polke, [Untitled], 1983, Synthetic polymer paint on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/36633