License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Michelangelo Buonarroti. Studies for the Libyan Sibyl (recto); Studies for the Libyan Sibyl and a small Sketch for a Seated Figure (verso), ca. 1510–11. The Metropolitan Museum of Art.