Acquired directly from the artist, 1973-1977
Nancy N. Schiffer and Val O. Bertoia, The World of Bertoia, Atglen, 2003, pp. 3, 180 for similar examples
Celia Bertoia, The Life and Work of Harry Bertoia: The Man, the Artist, the Visionary, Atglen, 2015, p. 137 for a similar example