Martinez, H. E. P.; Haag, H. P.; Moraes, M. L. Micronutrients in Pinus Caribaea Morelet. III. Corresponding, Fe, Mn and Zn Sufficiency and Deficiency Internal Levels. PAB 1992, 27 (9), 1339-1353. https://doi.org/10.1590/S1678-3921.pab1992.v27.3777.