1. Ahmed, R., and Graham, A. F., 1977, Persistent infections in L cells with temperature- sensitive mutants of reovirus, J. Virol. 23: 250.
2. Armen, R. C., Evermann, J. F., Truant, A. L., Laughlin, C. A., and Hallum, J. V., 1977, Temperature-sensitive mutants of measles virus produced from persistently infected HeLa cells, Arch. Virol. 53: 121.
3. Ashe, W. K., and Scherp, H. W., 1965, Antigenic variations in herpes simplex virus isolants from successive recurrences in herpes labialis, J. Immunol. 94: 385.
4. Brown, I. N., Brown, K. N., and Hills, L. A., 1968, Immunity to malaria: The antibody response to antigenic variation by Plasmodium knowlesi, Immunology 14: 127.
5. Burnstein, T., Jacobsen, L. B., Zeman, W., and Chen, T. T., 1974, Persistent infection of BSC-1 cells by defective measles virus derived from subacute sclerosing panencephalitis, Infect. Immun. 10: 1378.