 According to the American Library association, a challenge is an attempt to restrict access of a book through the removal of the text in curriculum and libraries.Specific reasons for the challenges in 2013 were "occult/Satanism, offensive language, religious viewpoint, sexually explicit" and similarly in 2008 of "occult/satanism, offensive language, religious viewpoint, sexually explicit, violence".A particularly vivid experience in the censorship of this book for the author, Rudolfo Anaya, was in 1981