Roél d'Haese, [Untitled], 1959, Ink on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/33976

Pierre Alechinsky, Study for The Snowman ([Étude] L'Homme des neiges), 1956, Ink and watercolor on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/35910

Octave Landuyt, Turtle, 1957, Ink, crayon, and gouache on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/37770

Roél d'Haese, [Untitled], 1959, Ink on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/33963

František Kupka, An Absolute (Une Absolue) from Art of Today, Masters of Abstract Art (Art d'aujourd'hui, maîtres de l'art abstrait), Album I, 1953 (original executed in 1952), One from a portfolio of sixteen screenprint reproductions, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/31875