Perdigão, António Manuel Machado, and Nuno José Quintino Rogado. “Soils and Geomorphological Development of the Haff Delta of the Vouga River (Portugal)”. Geografia Fisica e Dinamica Quaternaria 12, no. 1 (June 30, 1989): 59–61. Accessed October 22, 2026. https://gfdq.glaciologia.it/index.php/GFDQ/article/view/828.