Šperka, Roman, and Michal Halaška. “The Impact of Sales Service in MAREA Trading Simulation under Changing Environment Circumstances”. Equilibrium. Quarterly Journal of Economics and Economic Policy 12, no. 2 (June 30, 2017): 355–371. Accessed May 19, 2022. http://economic-research.pl/Journals/index.php/eq/article/view/41.