Wahjono, Hari Boedi, dan Fadli Rozaq. “Perbandingan Penggunaan Bahan Bakar High Speed Diesel Dan Biosolar Terhadap Emisi Gas Buang”. Jurnal Perkeretaapian Indonesia (Indonesian Railway Journal), vol. 2, no. 1, Maret 2018, hlm. 47-55, https://doi.org/10.37367/jpi.v2i1.45.