Immunoprotection in goats against Haemonchus contortus after immunization with cysteine protease enriched protein fractions Antonio Ruiz, José Manuel Molina, Jorge Francisco González, Magnolia María Conde, Sergio Martín and Yeray Isidro Hernández Vet. Res., 35 5 (2004) 565-572 DOI: 10.1051/vetres:2004032