Montazeri, N., Pourshamsian, K., Bayazi, M., & Kabiri, S. (2013). Synthesis of Spiro Heterobicyclic Rings Using Cellulose Sulfuric Acid Under Solvent Free Conditions. Asian Journal of Chemistry, 25(6), 3373–3375. https://doi.org/10.14233/ajchem.2013.13774