F. Hernández-Chavarría, L. Alzamora-González, and L. Herrero-Uribe, “Noncytopathic hepatitis A virus induces surface alterations in LLC-MK2 cells revealed by thin sections, negative staining, and scanning electron microscopy”, Rev. Biol. Trop., vol. 50, no. 2, pp. 519–523, Jun. 2002.