Goce, Boceski, and Vrtanoski Gligorce. “626.MYSTERY SHOPPERS AND NET PROMOTER SCORE TOOLS FOR CUSTOMER SATISFACTION IMPROVEMENT”. MECHANICAL ENGINEERING – SCIENTIFIC JOURNAL 38, no. 1 (June 12, 2021): 17–28. Accessed January 19, 2026. https://mesj.ukim.edu.mk/journals/article/view/38.