BROUGHTON, Paul L. Saskatchewan Lignite Under a Microscope. Blue Jay, [S. l.], v. 31, n. 2, 1970. DOI: 10.29173/bluejay3928. Disponível em: https://bluejayjournal.ca/index.php/bluejay/article/view/3928. Acesso em: 18 may. 2024.