1. A concentração do cloro em folhas de café;CATANI R.A.;An. Esc. Sup. Agric. "Luiz de Queiroz"
2. Commercial fertilizers;COLLINGS G.H.,1955
3. Diagnostic criteria for plants and soils;EATON F.M.
4. The water culture method for growing plants without soil;HOAGLAND D.R.;Calif. Agric Expt, Sta. Circ.
5. Calcium nutrition of higher plants;MARSCHNER H.;Neth. J. Agric. Sci.