Díaz, M. I. H.; González, V. M.; Hurtado, M. G.; Pulido, J. M. S.; Velóz, A. O. Nitrogen levels and their fractioning in gladiolus cultivation for Ferralitic Red soils. PAB 2008, 43 (1), 21-27. https://doi.org/10.1590/S1678-3921.pab2008.v43.7956.