Perilli, Nicola. «Lower Cretaceous Nannofossil Biostratigraphy of the Calpionella Limestone and the Palombini Shale in Southern Tuscany (Italy)». Spanish Journal of Palaeontology 12, no. 1 (marzo 1, 2022): 1–14. Accedido febrero 22, 2025. https://pasquin.uv.es/index.php/sjpalaeontology/article/view/23990.