Roberto Estopinán, Prisoner, 1967, Colored ink and ink on board, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/33104

Itur-ili, Tablet Recording a Business Letter, c. 1840–1730 BCE (Assyrian Colony), clay, hand made; impressed, Walters Art Museum, Baltimore. https://dartabase.art/cite/walters/48.1462

Roberto Estopinán, [Untitled], 1967, Transfer and ink on pink paper, The Museum of Modern Art, New York. https://dartabase.art/cite/moma/33123