Crespo-Bujosa, H. B., and R. L. Suárez Rodríguez. “Nootropics: Phytochemicals with Neuroprotective and Neurocognitive Enhancing Properties”. European Journal of Clinical and Experimental Medicine, vol. 17, no. 3, Sept. 2019, pp. 250–255, doi:10.15584/ejcem.2019.3.9.