Stewien, K. E., & Lacerda, J. P. G. de. (1975). Application of the neutralization index comparison technique to the intratypic serodifferentiation of type 1 and 3 poliovirus strains, using Hep-2 cell cultures . Revista De Saúde Pública, 9(2), 221-228. https://doi.org/10.1590/S0034-89101975000200012