4Perez-Schael I, Guntinas M J, Perez M, et al. Efficacy of the rhesus rotavirus-based quadrivalent vaccine in infante and young childen in Venezuela[ J] . N Engl J Med, 1997,337(17) : 1181 - 1187.
5David V,Katkin JP.Chronic and recurrent pneumonias in children[J].Semin Respir Infect,2002,17(1):72-84.