SINGH, Virendra. Artificial Ripening of Spruce Cones and Seed Maturity. Indian Forester, [S. l.], v. 115, n. 8, p. 590–594, 1989. DOI: 10.36808/if/1989/v115i8/9092. Disponível em: https://indianforester.co.in/index.php/indianforester/article/view/9092. Acesso em: 15 jan. 2026.