Synthesis, identification and thermal decomposition of double sulfites like `CU IND. 2´S`O IND. 3´`PONTO´MS`O IND. 3´`PONTO´`2H IND. 2´O (M=`CU´, `FE´, `MN´ or `CD´) - Silva, L. A.; Matos, Jivaldo do Rosário; Andrade, Jailson B. de (Thermochimica Acta, 2000)