Baghernejad, Bita (31 August 2011). "Application of p-toluenesulfonic Acid (PTSA) in Organic Synthesis". Current Organic Chemistry15 (17): 3091–3097. doi:10.2174/138527211798357074.Manba xatosi: Invalid <ref> tag; name "Baghernejad_2011" defined multiple times with different content