Vasily Yakovlovich Sitnikov, Birch Tree, (1961), Crayon on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/33339

Vasily Yakovlovich Sitnikov, Hillock, 1962, Oil and colored crayon on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/36759