1. Vitek C, Bisgard K, Lushniak B, Lyerla R, Zhilina N. Diphtheria epidemic in the Russian Federation: evidence for a decline in incidence [abstract G94]. In: Program and abstracts of the 36th Interscience Conference on Antimicrobial Agents and Chemotherapy (New Orleans). Washington, DC: American Society for Microbiology, 1996.
2. Expanded Programme on Immunization. Information System. Summary for World Health Organization European Region. Geneva: WHO, 1994; WHO/EPI/CEIS/94.2 EU.