Fontes, P. C. R., Sampaio, R. A. and Mantovani, E. C. (2000) “Tomato yield and potassium concentrations in soil and in plant petioles as affected by potassium fertirrigation”, Pesquisa Agropecuaria Brasileira, 35(3), pp. 575–580. doi: 10.1590/S1678-3921.pab2000.v35.5823.