T. Vijaya Kumar, C. Rama Koteswara Rao, K. Mukkanti, and P. S. Mainkar, “Polyethylene Glycol (PEG-400) as an Efficient and Recyclable Reaction Medium for One-Pot Synthesis of Substituted Pyrroles Under Catalyst-Free Conditions”, ajc, vol. 27, no. 4, pp. 1457–1461, Feb. 2015.