Viper Series available world wide
From the beginning David focused his books on the UK and American market however many don't realize they are also available in other amazon.com stores. This will allow you to download and read the book with the cost coming from your local currency instead of the British Pound or US Dollar. See below for some links to other Amazon market places you can buy the book from. But remember Amazon restricts purchases in some cases to regional stores, meaning you cannot buy from the American store if you live in the UK and vise versa. The nice thing about shopping in your local store is you pay in your currency and not a more expensive currency like the Pound Sterling.
Amazon.de - European market site
Amazon.es - Spanish market site
Amazon.com.mx - Amazon Mexico
Amazon.fr - Amazon France
Amazon.com.au - Amazon Australia
Amazon.ca - Amazon Canada