Clancey, W. J., M. Fehling, S. Russell, R. E. Fikes, M. Stickel, W. Bledsoe, R. E. Korm, W. B. Thompson, and D. R. Barstow. “AAAI News”. AI Magazine, vol. 10, no. 3, Sept. 1989, p. 16, doi:10.1609/aimag.v10i3.764.