GUPTA, M. K.; SINGH, R. P.; JHA, M. N. Soil Chemical Properties of Silver Fir and Spruce Forest Under Different Systems of Silviculture. I-Changes in Soil Nitrogen. Indian Forester, [S. l.], v. 115, n. 4, p. 235–242, 1989. DOI: 10.36808/if/1989/v115i4/9022. Disponível em: http://indianforester.co.in/index.php/indianforester/article/view/9022. Acesso em: 4 dec. 2025.