Bergh, J. v. d. (1991). Roman Opalka: Opaque Addition. Flash Art.
Cita Chicago (17th ed.)Bergh, Jos van den. "Roman Opalka: Opaque Addition." Flash Art 1991.
Cita MLA (8th ed.)Bergh, Jos van den. "Roman Opalka: Opaque Addition." Flash Art, 1991.
Atenció: Aquestes cites poden no estar 100% correctes.