Ollier, Cliff D. “Breccia-Filled Pipes: Distinguishing Between Volcanic and Non-Volcanic Origins”. Geografia Fisica e Dinamica Quaternaria 30, no. 1 (June 19, 2024): 63–76. Accessed December 22, 2024. https://www.gfdq.glaciologia.it/index.php/GFDQ/article/view/343.