Don’t buy any books.
Books on the topic of “real vampirism” are mostly written by media whores trying to make a quick buck, to “speak for the community” and to be invited to third class radio interviews just because of the free coffee.
You wouldn’t trust your picture of the world to someone who voluntarily works (if at all) only shortly before halloween as some kind of wierdo exhibit for very local main stream media, would you?
Spend your bucks on this instead, it’s at least a worthwhile read.