Poverty, dirt, infections and non-atopic wheezing in children from a Brazilian urban center oleh Cooper Philip J, Cruz Alvaro A, Prado Matildes, Alvim Sheila, Amorim Leila D, Esquivel Renata, Fiaccone Rosemeire, Cunha Sergio S, Barreto Mauricio L, Santos Darci N, Strina Agostino, Alcantara-Neves Neuza, Rodrigues Laura C