journals/expert/X91e, Frederick Hayes-Roth and Richard Fikes discuss the first decade of commercial AI., 3-14, 1991, IEEE Expert, 6, 5, http://dblp.uni-trier.de/db/journals/expert/expert6.html#X91e, http://csdl2.computer.org/dl/mags/ex/1991/05/x5003.pdf