A knowledge-based system for stacker crane control in a manufacturing environment. - Hirofumi Matsuo; Jen S. Shang; Robert S. Sullivan (IEEE Trans. Syst. Man Cybern., 1989)

Goal programs with -ni, -pi and -(ni+pi) objective functions. - Zhi Yong Zhang; Jen S. Shang (Eur. J. Oper. Res., 2001)