Li, Jian, and Zu-Pei Liang. “Synthesis and Structural Characterization of N-Propyl-7-Oxa-bicyclo[2,2,1]hept-5-Ene-2,3-Dicarboximide”. Asian Journal of Chemistry, vol. 25, no. 2, Sept. 2012, pp. 660-2, doi:10.14233/ajchem.2013.12108A.