Millati, R. , Purwandari, F. , Sanjaya, A. , Cahyanto, M. , Horvath, I. , Niklasson, C. , Taherzadeh, M. (2012), 'Use of NMMO Pretreatment for Biogas Production from Oil Palm Empty Fruit Bunch', World Academy of Science, Engineering and Technology, Open Science Index 65, International Journal of Chemical and Molecular Engineering, 6(5), 486 - 489.