Elias, Robert, and Graham Young. “Ordovician-Silurian Boundary Interval in the Williston Basin Outcrop Belt of Manitoba: A Record of Global and Regional Environmental and Biotic Change”. Geoscience Canada 39, no. 4 (January 24, 2013). Accessed April 24, 2024. https://journals.lib.unb.ca/index.php/GC/article/view/20019.