M. I. E. Halmi, M. S. Shukor, N. A. Masdor, N. A. Shamaan, and M. Y. Shukor, “Test of randomness of residuals for the modified Gompertz model used in the fitting the growth of sludge microbes on PEG 600”, J Environ Microbiol Toxicol, vol. 3, no. 1, pp. 9–11, Jul. 2015.