Wang, Y., Lu, G., & Wu, L. (2011). Silica Sulfuric Acid as Heterogeneous and Recoverable Catalysts for the Synthesis of Dithienylmethanes under Solvent-Free Conditions. Asian Journal of Chemistry, 23(9), 4221–4222. Retrieved from https://asianpubs.org/index.php/ajchem/article/view/10820