1. AGOL, V. I. AND CHUMAKOVA, M. YA. (1962) : An agar polysaccharide and d marker of poliovirus. Virology, 17, 221-223.
2. BARRON, A. L. AND KARZON, D. T. (1961) : Characteristics of echo 4 (Shropshire) virus isolated during epidemic of aseptic meningitis. J. Immunol., 87, 608-615.
3. BARRON, A. L. AND KARZON, D. T. (1965) : Studies of mutants of echovirus 6. I. Biologic and serologic characteristics. Am. J. Epidemiol., 81, 323-332.
4. CHOPPIN, P. W. AND EGGERS, H. J. (1962) : Heterogeneity of Coxsackie B4 virus : Two kinds of particles which differ in antibody sensitivity, growth rate, and plaque size. Virology, 18, 470-476.
5. CHUMAKOV, M. P., VOROSHILOVA, M. K., ZHEVANDROVA, V. I., MIRONOVA, L. L., ITZELIS, F. G. AND ROBINSON, I. A. (1956) : Isolation and study of immunologic type IV poliomyelitis virus. Probl. Virol., 1, 16-19.