A friend of mine is reading a novel by Benito Pérez-Galdós, one of the writers that Spanish director Buñuel admired and whose two novels, "Nazarin" and "Tristana," he decided to turn into a movie. 
In Galdós' 1892 novel, Tristana is aged 19 at the time Don Lope becomes her guardian and seducer. However, it's possible that Buñuel represented her as a still younger woman because he dressed Catherine Deneuve like a school-girl, with tresses and a school-cap in a few scenes. Perhaps Tristana's age came close to V.Nabokov's "Lolita" because Buñuel once said that "The most dangerous virgins are the thirteen-year olds."(attrib). Luis Buñuel's movie was shot eight years after Kubrick filmed the adventures of Humbert Humbert with his nymphet, probably without referencing either Nabokov's novel, or Kubrick's version. It's not the poignant theme of abused innocence and pedophilia that which made Nabokov's novel appreciated for the work of art that it certainly is, but a specific literary quality that is often obfuscated by its shocking overt theme... .  

http://www.youtube.com/watch?v=p8oC1mYxchQ