McCulloch, B.; Kuhn, H.G.; Dalbock, R.R.; Bigalke, R.D.
(Published by The Government Printer, Pretoria, 1984)
Haemonchus, Trichostrongylus, Ostertagia and Nematodirus worm populations of sheep based on differential
egg counts are considered in relation to climatological and topographical data. Late spring, summer and early
autumn ...