SEKHAWAT, Kapila; SHIVAY, Y S; KUMAR, Dinesh. Porductivity and nutrient uptake of spring sunflower (Helianthus annuus) as influenced by nitrogen sources, sulphur and boron levels*. The Indian Journal of Agricultural Sciences, Delhi, India, v. 78, n. 1, 2008. Disponível em: https://epubs.icar.org.in/index.php/IJAgS/article/view/9776. Acesso em: 27 oct. 2025.