TROIANO, S.; MARANGON, F. I Payments for Ecosystem Services a pro dal paisaç e dal ambient. Gjornâl Furlan des Siencis - Friulian Journal of Science, Udine, Italy, v. 15, n. 15, p. 59–67, 2011. Disponível em: https://www.gfs-fjs.net/index.php/gsf/article/view/158. Acesso em: 2 may. 2025.