A. P. Iswanto, N. A. Imron, and S. Priyanto, “Analysis of Understanding and Violation of the Early Warning System (EWS) on Accident Rates at Level Crosses with the Chi-Square Method”, JPI, vol. 5, no. 1, pp. 10–17, Mar. 2021, doi: 10.37367/jpi.v5i1.133.