Cornelis Ruhtenberg (November 18, 1923-2008) was an American artist known for Abstract figure, portrait, and still-life painting. In 1956, Cornelis Ruhtenberg married the American painter Jules Kirschenbaum.
Biography on Wikipedia (Google translation from German): https://bit.ly/30xdwol
Self-Portrait by Cornelis Ruhtenberg
ND / Oil on wooden panel / 12″x10-2/5″ / Private collection
Cornelis Ruhtenberg on Artnet: http://www.artnet.com/artists/cornelis-ruhtenberg/