Saeed, Bahjat Ali, and Rita Sabah Elias. “A DFT Study for the Structures and Electronic Spectra of 2,3-Dihydropyridine-4-Ones”. European Journal of Chemistry, vol. 2, no. 4, Dec. 2011, pp. 469-74, doi:10.5155/eurjchem.2.4.469-474.496.