I've never seen the entire study results available online but there have been a few writers mention the study.
Here's a quote from one of the articles:
The results from Dr. Mickey Hellickson’s recent culling study in South Texas are likely the most applicable to the average deer manager because of the intensity of the culling efforts and the size of the study area. Mickey and his colleagues intensively culled the smallest antlered bucks in all age classes for six straight years on 10,000 acres on the King Ranch in Texas. When the study was over, the average antler quality per age class was slightly SMALLER than when they started! While factors such as yearling buck dispersal off the study area could partially account for lack of impact, it clearly suggests that even intensive culling on this scale is unlikely to impact genetics.
I like the QDM method of shooting deer based on their age rather than the size of their antlers. I passed on a 2 1/2 year old this year that would have come close to scoring the same B&C score as the 6 1/2+ year old I ended up shooting. I tenatively agedhim based on toothwear but I sent off the insicors to be aged based on the cementum anulli method. Shooting the older buck was a much more rewarding experience.