Ruhrberg, K. (1986). Twentieth century art: Painting and sculpture in the Ludwig Museum. Rizzoli.
Cita Chicago Style (17a ed.)Ruhrberg, Karl. Twentieth Century Art: Painting and Sculpture in the Ludwig Museum. New York: Rizzoli, 1986.
Cita MLA (8a ed.)Ruhrberg, Karl. Twentieth Century Art: Painting and Sculpture in the Ludwig Museum. Rizzoli, 1986.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.