Polereczki, Zsolt, et al. “Analysis of the Groceries from Different Point of Wiev on the South Transdanubian Region With Mystery Shopping Method”. Acta Agraria Kaposváriensis, vol. 9, no. 1, Feb. 2005, pp. 107-22, https://journal.uni-mate.hu/index.php/aak/article/view/1740.