R. Ramesh, et al. “Effect of Mycorrhizal Inoculation (VAM) and Phosphorus Levels on Growth and Yield Attributes of Sunflower”. Global Journal of Science Frontier Research, vol. 18, no. D4, Mar. 2018, pp. 7-11, https://journalofscience.org/index.php/GJSFR/article/view/2271.