František Kupka, Girl with a Ball, c. 1908, Pastel on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/37352

František Kupka, Bather, (1906), Pastel and charcoal on gray paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/37271

Piet Mondrian, Red Amaryllis with Blue Background, c. 1907, Watercolor on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/38743

Piet Mondrian, Amstel River, 1907, Watercolor and charcoal on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/36627

Piet Mondrian, Chrysanthemum (recto) and Head in Profile (verso), 1906, Charcoal on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/34486

František Kupka, View from a Carriage Window, c. 1901, Gouache and watercolor on paper with cardboard overlay, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/34108

František Kupka, Prometheus, (1909), Gouache, watercolor, ink, and pencil on paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/36018

Piet Mondrian, Landzicht Farm: Compositional Study, c. 1905, Fabricated charcoal on blue laid paper, Art Institute of Chicago, Chicago. https://dartabase.art/cite/aic/88464