1. American Cyanamid Company , CYANEX(®) 923 Extractant , Wayne , USA ( 1991 ).
2. American Cyanamid Company , CYANEX(®) 925 Extractant , Wayne , USA ( 1991 ).
3. American Cyanamid Company , CYANEX(®) 921 Extractant , Wayne , USA ( 1991 ).
4. Extraction of sulphuric acid from technological solution of hydroxylamine sulphate