Sekhawat, Kapila, Y S Shivay, and Dinesh Kumar. “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, no. 1 (January 5, 2008). Accessed October 27, 2025. https://epubs.icar.org.in/index.php/IJAgS/article/view/9776.