S. Abbasalizadeh, M. A. Hejazi, and M. Pesaran Hajiabbas, “Kinetics of β-galactosidase Production by Lactobacillus bulgaricus During pH Controlled Batch Fermentation in Three Commercial Bulk Starter Media”, Appl Food Biotechnol, vol. 2, no. 4, pp. 39–47, Oct. 2015.