Detection of vitamin a deficiency in brazilian children living in the urban sone using the +S30DR test - Ferraz, Ivan Savioli; Daneluzzi, Julio Cesar; Vannucchi, Hélio; Jordão Junior, Alceu Afonso; Ricco, Rubens Garcia; Del Ciampo, Luiz Antonio; Dalboni, V.; Martinelli Júnior, Carlos Eduardo; Engelberg, Alexander Antony D'Angio; Bonilha, Luís Roberto de Castro Martins (International Vitamin A Consultative Group Meeting, 2001)