Karel Appel, Beast, 1956, Ink on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/32981

Karel Appel, [Untitled], 1959, Crayon on paper (recto); pencil on paper (verso), The Museum of Modern Art, New York. https://dartabase.art/cite/moma/37614

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