Been trying to kill this weed for several years now. I have a centipede/fescue lawn with sandy soil. I use turf builder or similar fertilizer four times a year and have put down pre emergent for the past two years. I have successfully eliminated about every weed EXCEPT for this one. I have sprayed with every weed killer for lawns I can find at times with heavier concentrations than recommended but have had little success. They are pretty easy to pull up and I have filled many 5 gallon buckets after pulling for hours but they just seem to come back. Any help identifying and advice on killing/controlling it is very much appreciated. Thanks