Álvarez-Vázquez, Carmen, and Robert H. Wagner. “A Revision of Annularia and Asterophyllites Species from the Lower Westphalian (Middle Pennsylvanian) of the Maritime Provinces of Canada”. Atlantic Geoscience 53 (March 8, 2017): 017–062. Accessed March 29, 2024. https://journals.lib.unb.ca/index.php/ag/article/view/24352.