Condensed tannis for biological control of gastrointestinal nematodes in sheep - Minho, Alessandro Pelegrine; Cabral Filho, Sergio Lucio Salomon; Bricarello, Patrícia Ana; Ranzini, R. R.; Bueno, Ives Cláudio da Silva; Abdalla, Adibe Luiz; Gennari, Solange Maria; Louvandini, Helder (Biennial Conference of the Society for Tropical Veterinary Medicine, 2003)