Putra, Theo Agytha. “Comparison Analysis of Quality of Ax-7 Advance Shelling Lubricants and Pertamina Enduro Racing Lubricants on Kawasaki Ninja 250cc Injeksi Motor”. Jurnal Teknik Mesin (Journal Of Mechanical Engineering), vol. 7, no. 3, Nov. 2018, pp. 113-8, doi:10.22441/jtm.v7i3.4033.