Traykov , Velichko, and Miroslava Hristova-Cherbadzhi. “Heterosis Breeding in Sunflower. Manifestation of Heterosis in the Traits Yield and Weight of 1000 Seeds”. Bulgarian Journal of Crop Science 63, no. 5 (October 28, 2026): 38–51. Accessed November 4, 2026. https://agriacad.eu/ojs/index.php/bjcs/article/view/7358.