SKJENNEBERG, S. Lars Hällbom; Nitrogenase regulation and ultrastructure of heterocystous cyanobacteria; free living and in lichen symbiosis. Rangifer, [S. l.], v. 2, n. 1, p. 52, 1982. DOI: 10.7557/2.2.1.431. Disponível em: https://septentrio.uit.no/index.php/rangifer/article/view/431. Acesso em: 16 jan. 2022.