Yang, Z., E. Pahkala, and T. Tupasela. “Lactose Hydrolysis by Free and Fibre-Entrapped β-Galactosidase from Streptococcus Thermophilus”. Agricultural and Food Science, vol. 2, no. 5, Sept. 1993, pp. 395-01, doi:10.23986/afsci.72665.