Donald Judd, [Untitled], 1966, Felt-tip pen on colored paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/37059

Donald Judd, [Untitled], 1971, Felt-tip pen on colored paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/37608

Donald Judd, [Untitled], 1971, Felt-tip pen on colored paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/37612