Piene, O. (2016). Otto Piene: Black melt & light rays. Galerie Ludorff (Düsseldorf).
Cita Chicago (17th ed.)Piene, Otto. Otto Piene: Black Melt & Light Rays. Düsseldorf: Galerie Ludorff (Düsseldorf), 2016.
Cita MLA (8th ed.)Piene, Otto. Otto Piene: Black Melt & Light Rays. Galerie Ludorff (Düsseldorf), 2016.
Atenció: Aquestes cites poden no estar 100% correctes.