Complex sentence: Some believe that vampire mythology is derived from a surge in vamprie forklore at the very end of the 19th century, a proportion of whom feel that those sources were taken from Sanguinarian studies and then given a fictional gloss to make them more appealing.
Split into simpler sentences: Some believe that vampire mythology is derived from a surge in vampire folklore at the very end of the 19th century. Some feel that those sources were taken from Sanguinarian studies and then given a fictional gloss to make them more appealing.