Najmus Tsaqib, et al. “Analysis of the Effect of Product Quality and Service Quality on Customer Loyalty Mediated by Customer Satisfaction at Kafe Kudu, Jalan Sei Petani, Medan City ”. International Journal of Economics and Management Research, vol. 5, no. 1, Jan. 2026, pp. 172-9, doi:10.55606/ijemr.v5i1.622.