Shokif, Ahmad, et al. “ANALISIS KUALITAS PELAYANAN SIM DI POLRES TUBAN DENGAN METODE FUZZY SERVQUAL, KUADRAN IPA, DAN INDEKS PGCV”. Prosiding SNasPPM, vol. 7, no. 1, Oct. 2022, pp. 201-9, http://prosiding.unirow.ac.id/index.php/SNasPPM/article/view/1237.