@article{CRCHIM_2013__16_9_829_0,
     author = {Zeba N. Siddiqui and Saima Tarannum},
     title = {Xanthan sulfuric acid: {An} efficient and biodegradable solid acid catalyst for the synthesis of bis(indolyl)methanes under solvent-free conditions},
     journal = {Comptes Rendus. Chimie},
     pages = {829--837},
     publisher = {Elsevier},
     volume = {16},
     number = {9},
     year = {2013},
     doi = {10.1016/j.crci.2013.04.013},
     language = {en},
}