V. Malyi, V. Tchulanov, A. Podkolzin, T. Lyadova, and S. Lavelin, “THE STUDYING OF GENOTYPES OF VIRAL HEPATITIS B AND D IN KHARKIV REGION”, J. V. N. Karazin Khark. Nat. Univ., Ser. Med., no. 4, pp. 56-59, 1.