SARKAR, R K; MALLICK, R B. Effect of nitrogen, sulphur and foliar spray of nitrate salts on performance ofspring sunflower (Helianthus annuus). The Indian Journal of Agricultural Sciences, Delhi, India, v. 79, n. 12, 2011. Disponível em: https://epubs.icar.org.in/index.php/IJAgS/article/view/2554. Acesso em: 27 oct. 2025.