E. Maul; R. Eibach (1999). "Vitis International Variety Catalogue". Information and Coordination Centre for Biological Diversity of the Federal Agency for Agriculture and Food. Archived from the original on 13 May 2012. Retrieved 15 April 2007.
E. Maul; R. Eibach (1999). "Vitis International Variety Catalogue". Information and Coordination Centre for Biological Diversity of the Federal Agency for Agriculture and Food. Archived from the original on 13 May 2012. Retrieved 15 April 2007.