KEEN, Gilbert R. Handbook on Aircraft Timbers. Indian Forester, [S. l.], v. 46, n. 4, p. 202–202, 1920. DOI: 10.36808/if/1920/v46i4/18317. Disponível em: https://indianforester.co.in/index.php/indianforester/article/view/18317. Acesso em: 21 feb. 2026.