Elkanzi, Nadia Ali Ahmed, et al. “Synthesis of Some New Spirocyclic β-Lactam and Spirocyclic Thiazolidin-4-One Derivatives”. European Journal of Chemistry, vol. 4, no. 3, Sept. 2013, pp. 195-02, doi:10.5155/eurjchem.4.3.195-202.777.