de Oliveira, N.M., Kennedy, J.P. and Selaive-Villarroel, A.B. (1993) “Age at first mating on lifetime productivity of corriedale ewes in southern Brazil”, Pesquisa Agropecuaria Brasileira, 28(6), pp. 743–750. doi:10.1590/S1678-3921.pab1993.v28.3933.