Plessas, S., C. Nouska, I. Mantzourani, Y. Kourkoutas, A. Alexopoulos, and E. Bezirtzoglou. “Microbiological Exploration of Different Types of Kefir Grains.” Fermentation 3, no.1 (2016):
Tamime, A. Y. Probiotic Dairy Products. Blackwell Publishing, 2007.
Yang, Zhennai, Eine Huttunen, Mikael Staaf, Göran Widmalm, and Heikki Tenhu. “Separation, Purification and Characterisation of Extracellular Polysaccharides Produced by Slime-Forming Lactococcus Lactis Ssp. Cremoris Strains.” International Dairy Journal 9, no. 9 (September 1999): 631–38.
Luo, Cheng and Shanggui Deng. “Viili as Fermented Food in Health and Disease Prevention: A Review Study.” Journal of Agricultural Science and Food Technology 2 (2016): 105–113.
Salminen, Edith. “There Will Be Slime.” Nordic Food Lab, April 10, 2014. http://nordicfoodlab.org/blog/2014/3/there-will-be-slime .
Smith, Andrew. The Oxford Encyclopedia of Food and Drink in America, vol. 1. Oxford University Press, 2004.