Galduróz, J. C. F., and E. de A. Carlini. “The Effects of Long-Term Administration of Guarana on the Cognition of Normal, Elderly Volunteers”. São Paulo Medical Journal, vol. 114, no. 1, Jan. 1996, pp. 1073-8, https://periodicosapm.emnuvens.com.br/spmj/article/view/1881.