See http://blog.inf.ed.ac.uk/atate/2018/01/21/ruth2-and-roth2/
Previously http://blog.inf.ed.ac.uk/atate/2018/01/21/ruth-2-0/
See http://blog.inf.ed.ac.uk/atate/2018/01/21/ruth2-and-roth2/
Previously http://blog.inf.ed.ac.uk/atate/2018/01/21/ruth-2-0/