CROSS, Robert. Report on the Investigation and Collecting of Plants and Seeds of the India-rubber Trees of Para and Ceara and Balsam of Copaiba. Indian Forester, [S. l.], v. 4, n. 1, p. 5–40, DOI: 10.36808/if/1878/v4i1/13284. Disponível em: http://indianforester.co.in/index.php/indianforester/article/view/13284. Acesso em: 4 dec. 2025.