Xue, Jun, et al. “Simultaneous Determination of Ten Nutrient Elements in the Leaf of Gannan Navel Oranges from Southern Jiangxi by ICP-AES With Microwave Digestion”. Asian Journal of Chemistry, vol. 24, no. 7, Mar. 2012, pp. 3075-7, https://asianpubs.org/index.php/ajchem/article/view/9311.