Campbell, A. T. and Athayde, M. L. F. (2014) “Effect of sowing date on the behavior of two genotypes of sunflower. I. Phenological and agronomical aspects”, Pesquisa Agropecuaria Brasileira, 23(4), pp. 371–378. doi: 10.1590/S1678-3921.pab1988.v23.13860.