Ramesh, P., and K. Bhaskar. “Polyethylene Gylcol (PEG-400) As an Efficient and Recyclable Reaction Medium for One-Pot Three-Component Synthesis of Imidazo[1,2-a]pyridine Derivatives”. Asian Journal of Chemistry, vol. 28, no. 11, Aug. 2016, pp. 2517-20, doi:10.14233/ajchem.2016.20061.