Romli, I., Fairuz Kharida, and Chandra Naya. “Determination of Customer Satisfaction of Tax Service Office Services Using C4.5 and PSO”. Jurnal RESTI (Rekayasa Sistem Dan Teknologi Informasi), Vol. 4, no. 2, Apr. 2020, pp. 296 -02, doi:10.29207/resti.v4i2.1718.