NAUTIYAL, N; SHARMA, C P; CHATTERJEE, C. Role of copper in improving the seed quality of sunflower (Helianthus annuus). The Indian Journal of Agricultural Sciences, Delhi, India, v. 69, n. 3, 2013. Disponível em: https://epubs.icar.org.in/index.php/IJAgS/article/view/26554. Acesso em: 28 oct. 2025.