Butts, B. (1991). Five centuries of drawing: Masterpieces from the Museum of Fine Arts, Leipzig; The Saint Louis Art Museum, February 2 - March 24, 1991 / Barbara Butts.
Lua i Stíl Chicago (17ú heag.)Butts, Barbara. Five Centuries of Drawing: Masterpieces from the Museum of Fine Arts, Leipzig; The Saint Louis Art Museum, February 2 - March 24, 1991 / Barbara Butts. Saint Louis, 1991.
Lua MLA (8ú heag.)Butts, Barbara. Five Centuries of Drawing: Masterpieces from the Museum of Fine Arts, Leipzig; The Saint Louis Art Museum, February 2 - March 24, 1991 / Barbara Butts. 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.