Anwar Hossain, Md., and Lee Hwei Voon. “Silica-Supported Fe(II), Co(II) and Ni(II) Complexes As Efficient Catalysts to Esterification of Levulinic Acid With Polyol”. Asian Journal of Chemistry 33, no. 8 (July 26, 2021): 1842–1848. Accessed May 5, 2024. https://asianpubs.org/index.php/ajchem/article/view/33_8_21.