SINGH, OM; GUPTA, P C. Effects of sowing time and irrigation on phenology and growing degree days of spring sunflower (Helianthus annuus). The Indian Journal of Agricultural Sciences, Delhi, India, v. 72, n. 7, 2014. Disponível em: https://epubs.icar.org.in/index.php/IJAgS/article/view/40962. Acesso em: 20 oct. 2025.