1. V. A. Asatiani, in: New Methods of Biochemical Photometry [in Russian], Moscow (1965), p. 495.
2. W. van Heyningen, in: H. Neurath and K. Bailey, The Proteins [Russian translation], Vol. 3, Part 1, Moscow (1958), p. 639.
3. V. K. Golshmid and I. M. Mikhailova, Zh. Mikrobiol., No. 1, 46 (1967).
4. R. Dubos, Biochemical Factors in Microbial Diseases [Russian translation], Moscow (1957).
5. I. N. Morgunov, Bacterial Toxins and Toxoids [in Russian], Kiev (1959).