[1]
M. M. Utumi, P. H. Monnerat, P. R. G. Pereira, P. C. R. Fontes, and V. de P. C. Godinho, “Macronutrient deficiencies in stevia: visual symptoms and effects on growth, chemical composition, and stevioside production”, PAB, vol. 34, no. 6, pp. 1039–1043, Jun. 1999.