1. The Metallurgy of Non-ferrous Metals;Gowland,1921
2. McArthur, J.W., Forrest, R.W. and Forrest, W., US Patents 403, 202, 428, 137 and 418, 138 (1889).
3. Extraction of gold from finely dissimilated gold ores by use of acid thiourea solution;Pyper,1981
4. A study of the leaching of gold, and silver by acid thiourea;Chen;Hydrometallurgy,1980