Piskrzyńska, Katarzyna, and Szymon Cieślar. “The Efficiency in Microenterprises Versus the Organization of Working Time ”. Forum Scientiae Oeconomia, vol. 3, no. 4, Dec. 2015, pp. 79-89, https://ojs.wsb.edu.pl/index.php/fso/article/view/247.