Westgate, John A., and Nancy D. Briggs. “Dating Methods of Pleistocene Deposits and Their Problems: V. Tephrochronology and Fission-Track Dating”. Geoscience Canada 7, no. 1 (April 4, 1980). Accessed May 4, 2024. https://journals.lib.unb.ca/index.php/GC/article/view/3198.