PALO, R. Thomas. Usnic acid, a secondary metabolite of lichens and its effect on in vitro digestibility in reindeer. Rangifer, Tromsø, Norway, v. 13, n. 1, p. 39–43, 1993. DOI: 10.7557/2.13.1.1071. Disponível em: https://septentrio.uit.no/index.php/rangifer/article/view/1071. Acesso em: 6 may. 2026.