Betancourth García, Carlos, et al. “Soil Coverage Evaluation With Calendula (Calendula Officinalis L.), Crotalaria (Crotalaria Sp. L.) and Oat (Avena Sp. L.) in Meloidogyne Spp. Control in Quito Orange (Solanum Quitoense Lam.)”. Revista De Ciencias Agrícolas, vol. 28, no. 2, July 2011, pp. 43-57, https://revistas.udenar.edu.co/index.php/rfacia/article/view/13.