SCHILLING, E.E., DA COSTA, F.B., LOPES, N.P. and HEISE, P.J. (2003) “BRAZILIAN SPECIES OF VIGUIERA (ASTERACEAE) EXHIBITLOW LEVELS OF ITS SEQUENCE VARIATION”, Edinburgh Journal of Botany, 57(3), pp. 323–332. doi:10.1017/S0960428600000330.