VARSHNEY, A C; NAIK, R K; NANDY, S M; PRAJAPATI, G S; NARANG, S. Determination of angle of penetration of soil working tools in clay soil. The Indian Journal of Agricultural Sciences, Delhi, India, v. 76, n. 1, 2011. Disponível em: https://epubs.icar.org.in/index.php/IJAgS/article/view/2597. Acesso em: 6 jun. 2026.