1. European Council, General Rules on Definition, Description and Presentation of Spirituous Beverages, Regulation No. 1576/89 of 29 May 1989, Official Diary of European Community No. L160/1, 1989.
2. The President of the Italian Republic, Rules on Production and Commercialisation of Spirituous Beverages, Decree No.297, 16 July 1997, Official Gazette of Italian Republic No.213, 1997.
3. http://www.altrovino.com/grappa.html
4. Trace element analysis of Cretan wines and wine products
5. Classification of Venezuelan spirituous beverages by means of discriminant analysis and artificial neural networks based on their Zn, Cu and Fe concentrations