El-Shaaer, Hafez Mohamed, et al. “Synthesis, Antifungal Activity and Semi-Empirical AM1-MO Calculations of Some New 4-Oxo-4H-Chromene Derivatives”. European Journal of Chemistry, vol. 2, no. 2, June 2011, pp. 158-62, doi:10.5155/eurjchem.2.2.158-162.381.