@book{86694,
	author = {Melo, Francisco de Brito },
	title = {Critical levels and sufficiency ranges for leaf nutrient diagnosis in cowpea grown in the Northeast region of Brazil},
	note = {
Publicação on-line; 23 ref.; 6 tables; Summaries (En, Pt)},
	url = {https://www.scielo.br/j/rca/a/4k8yF7bLSmdJDLbLLTzyxwd/?format=pdf&lang=en}
}