El-Shaaer, Hafez Mohamed. “An Efficient Synthesis of Some New Isolated and Fused 2-Oxo-2H-Chromene Derivatives As Antimicrobial and Antitumor Agents”. European Journal of Chemistry, vol. 4, no. 2, June 2013, pp. 138-45, doi:10.5155/eurjchem.4.2.138-145.749.