Barcelos, J. P. Q. (2016) “DIAGNOSIS OF NITROGEN AND NICKEL REQUIREMENTS FOR COTTON PLANTS USING A PORTABLE CHLOROPHYLL METER”, Revista Brasileira de Engenharia de Biossistemas. Tupã, São Paulo, Brazil, 10(1), pp. 97–106. doi: 10.18011/bioeng2016v10n1p97-106.