Grenfell, B. T., and G. Smith. 1983. Population biology and control of ostertagiasis in first year grazing calves. Proc. Soc. Vet. Epid. Prevent. Medicine 2:54-62.
Grenfell, B. T., and G. Smith. 1983. Population biology and control of ostertagiasis in first year grazing calves. Proc. Soc. Vet. Epid. Prevent. Medicine 2:54-62.