H. W. L. Carvarvalho, C. A. Pachego, M. X. Santos, E. E. G. Gama, and R. Magnavaca, “Three cycles of selection among and within half-sib families on maize population BR 5028 - São Francisco in the brazilian northeast”, PAB, vol. 29, no. 11, pp. 1727–1733, Nov. 1994.