Optimization and validation of a LIBS method for the determination of macro and micronutrients in sugar cane leaves - Nunes, Lidiane Cristina; Braga, Jez Willian Batista; Trevizan, Lilian Cristina; Souza, Paulino Florêncio de; Carvalho, Gabriel Gustinelli Arantes de; Santos Junior, Dario; Poppi, Ronei J; Krug, Francisco José (Journal of Analytical Atomic Spectrometry, 2010)