[Prevalence of antibodies against hepatitis A virus (HAV) in a population of Mexican children]. - Ramirez Mayans JA; Cervantes Bustamante R; Jiron Castro R; Oyervides Garcia CI; Mata Rivera N; Navarrete Delgadillo Natividad MA; Sosa Martinez MC (Acta gastroenterologica Latinoamericana, 1997)