Colalongo, Maria Luisa, Giancarlo Pasini, Giuseppe Pelosio, Sergio Raffi, Domenico Rio, Giuliano Ruggieri, Samuele Sartoni, Raimondo Selli, and Rodolfo Sprovieri. “The Neogene Quaternary Boundary Definition: A Review and Proposal”. Geografia Fisica e Dinamica Quaternaria 5, no. 1 (June 30, 1982): 59–68. Accessed April 3, 2025. https://www.gfdq.glaciologia.it/index.php/GFDQ/article/view/967.