Soleh, Muhamad, et al. “MULTI OBJECT DETECTION AND TRACKING USING OPTICAL FLOW DENSITY – HUNGARIAN KALMAN FILTER (OFD - HKF) ALGORITHM FOR VEHICLE COUNTING”. Jurnal Ilmu Komputer Dan Informasi, vol. 11, no. 1, Feb. 2018, pp. 17-26, doi:10.21609/jiki.v11i1.581.