1. Agatzini, S., Dimaki, D., 1991. Recovery of nickel and cobalt from low-grade nickel oxide ores by heap leaching with diluted sulphuric acid room temperature. Greek Patent 910100234.
2. Çeap leaching of poor nickel-laterites by sulphuric acid at ambient temperature;Agatzini,1994
3. Extraction of nickel and cobalt from Greek low-grade nickel oxide ores by heap leaching;Agatzini,1997
4. Agatzini, S., Oustadakis, P., Zafiratos, J., 1999. Removal of aluminum and chromium from nickel—cobalt sulphate solutions, Greek Patent no 1,003,419.
5. Removal of aluminum and chromium from leach liquors produced by sulphuric acid leaching of nickel oxide ores;Agatzini,2001