Filho, G.N.S. and Vidor, C. (2001) “Phosphate solubilizing activity of microorganisms in the presence of nitrogen, iron, calcium and potassium”, Pesquisa Agropecuaria Brasileira, 36(12), pp. 1495–1508. doi:10.1590/S1678-3921.pab2001.v36.6284.