Aditiawati, P., Pujobroto, A., Rudiansyah, I. and Rahmadi, H. (2013) “Effect of Stimulants on Biogenic Methane Formation and Dynamics of Bacterial Population”, Journal of Mathematical and Fundamental Sciences, 45(3), pp. 274-285. doi: 10.5614/j.math.fund.sci.2013.45.3.6.