If you're wondering about the quote in "Twilight" from Montague Summers I can explain.

Montague Summers was a 19th century British clergyman and writer. Most of his Книги were nonfiction works about witches and vampires.

The quote in "Twilight" is taken from the introduction to the book "The Vampire:His Kith And Kin". A volume that covers vampire legends from around the world. Along with familiar Europeon Вампиры that most are familiar with the book also covers vampire legends from Africa, Asia and other parts of the world.

This an excellent work about vampire legends that is worth seeking out.