A. E. Johnston, “Understanding Potassium and Its Use in Agriculture”, 2003, European Fertilizer Manufacturers Association, Brussels, Belgium, 5–35.
Amarilis de Varennes, “Produtividade dos Solos e Ambiente”, 2003, Escolar Editora, Lisboa, Portugal, 349–352.
M. Miró and W. Frenzel, Microchim. Acta, 2004, 148, 1.
M. A. Segundo and L. M. Magalhães, Anal. Sci., 2006, 22, 3.
V. Cerdà, R. Forteza, and J. M. Estela, Anal. Chim. Acta, 2007, 600, 35.
J. Buanuam, M. Miró, E. H. Hansen, J. Shiowatana, J. M. Estela, and V. Cerdà, Talanta, 2007, 71, 1710.
M. Valcárcel and M. Gallego, Talanta, 1997, 44, 1509.
A. Carlosena, M. Gallego, and M. Valcárcel, J. Anal. At. Spectrom., 1997, 12, 479.
M. de la Guardia, V. Carbonell, A. Morales-Rubio, and A. Salvador, Talanta, 1993, 40, 1609.
P. Viñas, N. Campillo, I. L. García, and M. H. Córdoba, Anal. Chim. Acta, 1993, 283, 393.
C. C. Oliveira, R. P. Sartini, and E. A. G. Zagatto, Anal. Chim. Acta, 2000, 413, 41.
C. C. Oliveira, E. A. G. Zagatto, A. N. Araújo, and J. L. F. C. Lima, Anal. Chim. Acta, 1998, 371, 57.
M. Hulsman, M. Bos, and W. E. van der Linden, Anal. Chim. Acta, 1996, 324, 13.
M. Hulsman, M. Bos, and W. E. van der Linden, Anal. Chim. Acta, 1997, 346, 351.
I. Walinga, W. van Vark, V. J. G. Houba, and J. J. van der Lee, “Plant Analysis Procedures”, 1989, Part 7, Wageningen Agricultural University, Wageningen, Netherlands.
M. I. G. S. Almeida, M. A. Segundo, J. L. F. C. Lima, and A. O. S. S. Rangel, Talanta, 2004, 64, 1283.
J. C. Miller and J. N. Miller, “Statistics and Chemometrics for Analytical Chemistry”, 5th ed., 2005, Pearson Education, Harlow, UK.