C. Fazekas and A. Péntek, “The impact of foliar fertilization on the nectar production and apicultural value of sunflower (Helianthus annuus l.)”, GEORGIKON AGRICUL, vol. 20, no. 2, pp. 14–23, Dec. 2016, Accessed: Dec. 05, 2025. [Online]. Available: https://journal.uni-mate.hu/index.php/gfa/article/view/6671