COLBERG, O.; BEALE, A. Four levels of nitrogen fertilization in two onion (Allium cepa) varieties. The Journal of Agriculture of the University of Puerto Rico, [S. l.], v. 75, n. 1, p. 1–10, 1991. DOI: 10.46429/jaupr.v75i1.3542. Disponível em: https://revistas.upr.edu/index.php/jaupr/article/view/3542. Acesso em: 2 oct. 2022.