Tiwari, Vivek, and Rashmi Singhai. 2010. “Intermolecular Inter-Ligand Interaction in Mixed Ligand Complexes of Lanthanides(III) Involving Histidine and Some Amino Acids ”. Asian Journal of Chemistry 15 (3):1814-16. https://asianpubs.org/index.php/ajchem/article/view/21910.