Chojnacki, Andrzej, and Hanna Borzęcka. “Assessment of Economic Activity of the Company on the Base of Fuzzy Inference Rules”. Studia Informatica. System and Information Technology, vol. 12, no. 1, June 2009, pp. 33-45, https://czasopisma.uws.edu.pl/studiainformatica/article/view/2818.