Complex sentence: Ruth Kligman (January 25,1930--March 1,2010) was an American abstract artist and writer most commonly known as the muse of several other American artists of the mid- 20th century including Jackson Pollock and Willem de Kooning.
Split into simpler sentences: Ruth Kligman (January 25,1930--March 1,2010) was an American abstract artist and writer. She was notable as the muse of prominent American artists of the mid- 20th century including Jackson Pollock and Willem de Kooning.