Ibrahim, M. A., Hassanin, H. M., Gabr, Y. A.-A., & Alnamer, Y. A.-S. (2010). Novel heterocyclic derivatives of pyrano[3,2-c]quinolinone from 3-(1-ethy1-4-hydroxy-2-oxo-2(1H)-quinolin-3-yl)-3-oxopropanoic acid. European Journal of Chemistry, 1(3), 195–199. https://doi.org/10.5155/eurjchem.1.3.195-199.91