PETERS SOLÓRZANO, Gertrud. Upala: Historical Reconstruction of its Landscape by Ancient Settlements. Revista de historia., [S. l.], n. 78, p. 33–62, 2018. DOI: 10.15359/rh.78.3. Disponível em: https://www.revistas.una.ac.cr/index.php/historia/article/view/11286. Acesso em: 25 apr. 2026.