Adolph von Menzel, Head of a Bearded Man, 1884, Graphite, The Metropolitan Museum of Art, New York. https://dartabase.art/cite/met/334928

Adolph von Menzel, Doctor and Patient, 1899, Graphite, The Metropolitan Museum of Art, New York. https://dartabase.art/cite/met/334927

Adolph von Menzel, Woman with a Crushed Velvet Hat, 1894, Graphite, The Metropolitan Museum of Art, New York. https://dartabase.art/cite/met/334929

Joaquín Torres-García, Composition, 1932, Ink and pencil on brown paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/38816