Nadel, Jeffrey L. “Incidence and Risk Factors for Cognitive Impairment in Rural Elderly Populations in Costa Rica”. Revista de Biología Tropical 62, no. 3 (September 1, 2014): 869–876. Accessed December 7, 2025. https://archivo.revistas.ucr.ac.cr/index.php/rbt/article/view/14058.