Verhulst, J., & Nijeboer, A. (2007). Direct Democracy: Facts and Arguments about the Introduction of Initiative and Referendum. pages 37-38. Democracy International, Brussels.
Thanks to John Noyce for sending me this. Check out his blog: http://www.historye.blogspot.com/
It's interesting that the question of selfhood - once left to mystics and philosophers - is now seen as worth inquiry by scientists, and even legislators.