Mohammed, S.E. and Baharom, M.B. and Aziz, A.R.A. and Firmansyah (2011) The effects of fuel-injection timing at medium injection pressure on the engine characteristics and emissions of a CNG-DI engine fueled by a small amount of hydrogen in CNG. International Journal of Hydrogen Energy, 36 (18). pp. 11997-12006. ISSN 03603199