Stehouwer, H.P., Aarts, E.H.L., & Wessels, J. <https://pure.iiasa.ac.at/view/iiasa/2510.html>  (1995).  Multi-layered perceptions for on-line lot sizing.   In: Proceedings of the INRIA/IEEE Symposium on Emerging Technologies and Factory Automation, Vol. 3.