Johannes Itten, Female Nude (Weiblicher Akt), (c. 1917), Charcoal and pencil on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/37497

Johannes Itten, The Eavesdropper (Horchende), 1918, Crayon, charcoal and pencil on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/33967

Johannes Itten, Untitled (Postcard), 1918, Pencil on postcard, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/37586