@article {500,
	title = {Developing and running expert systems with PESYS},
	journal = {Future Generation Computer Systems},
	volume = {3},
	number = {3},
	year = {1987},
	pages = {189-199},
	isbn = {0167-739X},
	url = {FGCS1988.pdf},
	author = {Georgios I. Doukidis and Edgar A. Whitley}
}
