Renal involvement in Henoch-Schönlein purpura: a multivariate analysis of initial prognostic factors - Almeida, José Luiz J. de; Campos, Lúcia Maria A.; Paim, Luciana B.; Leone, Claudio; Koch, Vera Herminia K.; Silva, Clovis Artur Almeida da (Jornal de Pediatria, 2007)