P.K. KINGRA, PRABHJYOT KAUR, MANDEEP KAUR KHEHRA, and S. S. HUNDAL. “Thermal Requirement and Heat Use Efficiency of Sunflower (Helianthus Annus L.) in Punjab”. Journal of Agrometeorology 9, no. 2 (December 1, 2007): 223–230. Accessed April 1, 2025. https://journal.agrimetassociation.org/index.php/jam/article/view/1132.