Balthus (Baltusz Klossowski de Rola), Study for the painting La Chambre Turque, 1963, Pencil and watercolor on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/37888

Balthus (Baltusz Klossowski de Rola), Study of a Nude, (1964), Pencil on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/37884