Mreła, A., and O. Sokolov. “Compositions of Fuzzy Relations Applied to Veryfication Learning Outcomes on the Example of the Major ‘Geodesy and Cartography’”. Journal of Education, Health and Sport, vol. 5, no. 5, May 2015, pp. 183-92, https://apcz.umk.pl/JEHS/article/view/2676.