Quinlan, J.; Steyn, H.P.; De Vos, D.; Du Toit, P.J.
(Pretoria : The Government Printer, 1941)
1. Ninety-nine maiden Merino ewes, between the ages of 27 and 33 months, kept in an enforced environment in "dry lot" were submitted to a 3 hourly test for oestrus, from 6 p.m. to 6 a.m., at the commencement of the usual ...