FREDEN, E. G.; SETH, V. K.; TOMAR, M. S. Use of Helicopter in Preinvestment Survey of Forest Resources, India. Indian Forester, [S. l.], v. 95, n. 9, p. 604–610, 1969. DOI: 10.36808/if/1969/v95i9/26151. Disponível em: https://indianforester.co.in/index.php/indianforester/article/view/26151. Acesso em: 29 oct. 2025.