Al-Taey, Duraid K. A., et al. “The Beneficial Effects of Bio-Fertilizers Combinations and Humic Acid on Growth, Yield Parameters and Nitrogen Content of Broccoli Grown under Drip Irrigation System”. Bulgarian Journal of Agricultural Science, vol. 25, no. 5, Oct. 2019, pp. 959-66, https://agriacad.eu/ojs/index.php/bjas/article/view/3856.