1. I. Ya. Uchitel' and É. L. Khasman, In book: Problems in Infections Pathology and Immunology [in Russian], Moscow (1963), p. 55.
2. I. Ya. Uchitel' and É. L. Khasman, Vestn. Akad. Med. Nauk SSSR, No. 3 (1964), p. 23.
3. J. Sterzl, Uspekhi Sovr. Biol., Vol. 48, No. 3 (1959), p. 356.
4. H. C. Anderson and M. McCarty, J. Exp. Med., Vol. 93 (1951), p. 25.
5. J. V. Sparck, Acta Path. Microbiol. Scand, Vol. 46 (1959), p. 206.