Spies, W. (1969). Renato Guttuso: Werke 1968/69. Michael Hertz.
Cita Chicago (17th ed.)Spies, Werner. Renato Guttuso: Werke 1968/69. Bremen: Michael Hertz, 1969.
Cita MLA (8th ed.)Spies, Werner. Renato Guttuso: Werke 1968/69. Michael Hertz, 1969.
Atenció: Aquestes cites poden no estar 100% correctes.