H. Khdheyer, F. (2010). Role of the Caffeine (1,3,7 trimethylxanthine) on Callus Initiation, Growth and Differentiation from Hypocotyls of Sun Flower Helianthus annuus L. Rafidain Journal of Science, 21(7), 87–105. https://doi.org/10.33899/rjs.2010.35152