Seasonal variation of the major secondary metabolites present in the extract of Eremanthus mattogrossensis Less(Asteraceae: Vernonieae) leaves - Gouvea, Dayana Rubio; Gobbo Neto, Leonardo; Sakamoto, Humberto T.; Lopes, Norberto Peporine; Lopes, Joao Luis Callegari; Meloni, Fernando; Amaral, Juliano Geraldo (Química Nova, 2012)