Sekhawat, K., Shivay, Y.S. and Kumar, D. (2008) “Porductivity and nutrient uptake of spring sunflower (Helianthus annuus) as influenced by nitrogen sources, sulphur and boron levels*”, The Indian Journal of Agricultural Sciences, 78(1). Available at: https://epubs.icar.org.in/index.php/IJAgS/article/view/9776 (Accessed: 27 October 2025).