System of recommendations for a sustainable tourism product in the Piedra Blanca Waterfall, Canton Bucay. Neutrosophic Computing and Machine Learning. ISSN 2574-1101, [S. l.], v. 38, p. 311–320, 2025. Disponível em: http://fs.unm.edu/NCML2/index.php/112/article/view/812.. Acesso em: 9 dec. 2025.