C. R. B. Cancio, R. S. de Castro, L. de A. Coelho, J. H. de A. Rangel, and J. C. de Oliveira, “Age at first parturition, parturition intervals, and milk production in saanen, marota and crossbred goat’s”, PAB, vol. 27, no. 1, pp. 53–59, Jan. 1992.