Hamama, Wafaa S., Hanafi Hassan Zoorob, and Osama Abd El-Magid. 2011. “Fused and Spiro Nitrogen Heterocycles of Quinuclidine and Its C-Nucleosides”. European Journal of Chemistry 2 (4):552-57. https://doi.org/10.5155/eurjchem.2.4.552-557.265.