ÁLVAREZ-VÁZQUEZ, C.; WAGNER, R. H. A revision of Annularia and Asterophyllites species from the lower Westphalian (Middle Pennsylvanian) of the Maritime Provinces of Canada. Atlantic Geology, [S. l.], v. 53, p. 017–062, 2017. DOI: 10.4138/atlgeol.2017.002. Disponível em: https://journals.lib.unb.ca/index.php/ag/article/view/24352. Acesso em: 30 nov. 2021.