Weiss, N., Schillinger, U., Kandler, O. 1983. Lactobacillus lactis, Lactobacillus leichmannii and Lactobacillus bulgaricus subjective synonyms of Lactobacillus delbrueckii subsp. lactis comb. nov. and Lactobacillus delbrueckii subsp. bulgaricus comb. nov. Systematic and Applied Microbiology. 4 : 552-557.