I just found this in one of those papers (http://www.cs.princeton.edu/~appel/papers/wand-frame.pdf http://www.cs.princeton.edu/~appel/papers/wand-frame.pdf). In

I just found this in one of those papers (http://www.cs.princeton.edu/~appel/papers/wand-frame.pdf http://www.cs.princeton.edu/~appel/papers/wand-frame.pdf). In the text: > Magic wands are famously difficult to control [15].... In the references: 15. J. K. Rowling. Harry Potter and the Philosopher’s Stone. Bloomsbury Childrens, London, 1997.