Herbicides that translocate to the roots help kill some.

A disk that cuts the rizomes into smaller pieces helps reduce their reserves.

If the ripper triples yield then it needs to be used also.

I would spray it with one of the herbicides recomended above.

A week later I would disk it as deep as possible.

A week later I would disk it at a different angle.

Clean tillage has been one of the ways of controling it since day one.

I would continue the weekly or twice monthly diskings as long as possible.

I would use the ripper latter in the season.  

My experience has been the rizomes are close enough to the surface that you can get them with a deep disking.

That may be different in your area.