Nut grass infestation:Need help eliminating

[MLasseigne]

My garden beds are infested with nut grass (also known as coconut grass or
coco grass).  Just pulling the weed up seems to cause the plant to
multiply.
I have tried digging the tubers up, which works, but have had problems in
finding them.  Besides, the beds are too large for this to be a feasible
solution. 

I need good advice on eradicating this weed.  Any suggestions would be
appreciated.