Kurniawan, Dwi Ardianta, et al. “Ketahanan Bisnis Perkeretaapian Di Masa Pandemi COVID - 19”. Jurnal Perkeretaapian Indonesia (Indonesian Railway Journal), vol. 5, no. 2, Nov. 2021, pp. 12-21, https://doi.org/10.37367/jpi.v5i2.156.