Solasi, Angel Dario, and Claudio Mario Mundstock. “Sowing Dates and Capitulum Characteristics of Sunflower Cultivars”. Pesquisa Agropecuaria Brasileira, vol. 27, no. 6, June 1992, pp. 873-9, doi:10.1590/S1678-3921.pab1992.v27.3721.