Farminta, V., S. Mujiharjo, and K. C. Susena. “QUALITY SERVICES ANALYSIS OF SPORT SERVICES INDUSTRY BY SERVQUAL AND IMPORTANCE PERFORMANCE ANALISYS (IPA) METHOD”. Jurnal Agroindustri, vol. 5, no. 1, May 2015, pp. 57-74, doi:10.31186/j.agroindustri.5.1.57-74.