BANSAL, R L; NAYYAR, V K. Critical limit of manganese for sunflower (Helianthus annuus) in Ustochrepts. The Indian Journal of Agricultural Sciences, Delhi, India, v. 65, n. 3, 2012. Disponível em: https://epubs.icar.org.in/index.php/IJAgS/article/view/18667. Acesso em: 29 oct. 2025.