Sound art before sound art ON AIR: The sound of the material in the art of the 1950s to 1970s, by Kunstmuseen Krefeld, Krefeld, Germany, Exhibited from November 25, 2022 to February 26, 2023, https://kunstmuseenkrefeld.de/en/Exhibitions/2022/On-Air-Der-Klang-Des-Materials-In-Der-Kunst-Der-1950er-Bis-1970er-Jahre