To this end, Wine Grape Varieties of the World from a European Point of View offers good support by listing more than 900 varieties.
The book first lists the ten most favoured grape varieties, and after this the varieties are listed by countries and by wine regions. Finally, you can find maps of wine regions and an alphabetical index of the wine grape varieties.
This reference book is the same size as the screen of a tablet, handy for viewing at your home as well as packing it in your bag or suitcase as a guide to local wines.
It is also available as an e-book for all platforms. This makes it easy to search all the grape varieties for instance of a particular region or a particular country.