Laurenti, Stefano, and Paolo Viali. “International Waterbirds Census (IWC) Data, Collected in the Terni Province (Umbria): Beginning of the S. Liberato Bird Sanctuary”. Rivista Italiana di Ornitologia 82, no. 1-2 (September 30, 2012). Accessed November 21, 2024. https://sisn.pagepress.org/rio/article/view/173.