SINGHAL, R. M.; SHARMA, S. D. Infra-red Spectroscopy of the Soil Humic Acids of the Sal (<I>Shorea robusta</I>) Forests of Doon Valley. Indian Forester, [S. l.], v. 105, n. 9, p. 658–663, 1979. DOI: 10.36808/if/1979/v105i9/11359. Disponível em: http://indianforester.co.in/index.php/indianforester/article/view/11359. Acesso em: 5 dec. 2025.