Du Toit, R.; Fiedler, O.G.H.; Alexander, R.A.; Clark, R.; Louw, J.G.; De Kock, V.E.
(Published by The Government Printer, Pretoria, 1954)
The duration of protection afforded to sheep against blowfly strike by the
treatment of the wool with an insecticide possessing good powers of diffusion is
correlated with the length of wool at the time of treatment. ...