ROLDÁN REGÚS, Julián. Cobalt and Copper Contents of Some Tropical Soils and Grasses from Puerto Rico. The Journal of Agriculture of the University of Puerto Rico, [S. l.], v. 53, n. 4, p. 348–356, 1969. DOI: 10.46429/jaupr.v53i4.11148. Disponível em: https://revistas.upr.edu/index.php/jaupr/article/view/11148. Acesso em: 7 may. 2024.