6J.Uriarte,M.M.Llorente,J.Valderrabano.Seasonal chan-ges of gastrointestinal nematode burden in sheep under an intensive grazing system[J].Veterinary Parasitology,2003,118(2),79-92.
7S.M.Githigia,S.M.Thamsborg,M.Larsen.Effectiveness of grazing management in controlling gastrointestinal nema-todes in weaner lambs on pasture in Denmark[J].Veteri-nar Parasitology,2001,99(1),15-27.
8Anm K.Yadav,Veena Tandon.Gastrointestinal nematode infections of goats in a sub-tropical and humid zone of India[J].Veterinar Parasitology,1989,33 (2),135-142.
