Fakhrudiyanto, N. “Peran Unit Dikyasa Satuan Lalu Lintas Polres Purworejo Dalam Menekan Angka Kecelakaan Lalu Lintas: The Role of Dikyasa Traffic Unit Police of Purworejo Regional Police in Suppressing Traffic Accident Rates”. Advances in Police Science Research Journal, Vol. 1, no. 1, Jan. 2017, pp. 195-44, http://journal.akpol.ac.id/index.php/apsrj/article/view/22.