Aryamitra Pandey, Mr., et al. “Variation Symmetry Around Nd3+ Ion Saturated Solution of Medicinal Compounds With Reference to Judd-Ofelt Electronic Spectral Parameter”. Asian Journal of Chemistry, vol. 13, no. 1, Mar. 2010, pp. 319-22, https://asianpubs.org/index.php/ajchem/article/view/22573.