Potentiometric determination of stability constants of sulphite and cobalt (ii) in ionic strength 2.0 m ('NA' 'CL' 'O IND.4'). Use of matrix method - Cavalheiro, Eder Tadeu Gomes; Plepis, Ana Maria de Guzzi; Chierice, Gilberto Orivaldo; Neves, Eduardo Fausto de Almeida (Polyhedron, 1987)