lower right in black ink: A. WALKOWITZ 1911; lower left verso in blue ink: Dr P; lower right verso in graphite by unknown hand: D [circled]
(Zabriskie Gallery, New York); Olga Hirshhorn, Washington, DC; Corcoran Gallery of Art, Washington, DC 2004; acquired by the National Gallery of Art
- Walkowitz, Abraham. Improvisations of New York: A Symphony in Lines. Girard, Kansas: Haldeman-Julius Publications, 1948.