There are polls released almost daily pertaining to the Democratic nomination. In order to attend the September 12–13 round of debates, candidates need to get donations from 130,000 unique donors and attain at least 2% in 4 polls (national or early state) from some list of approved pollsters. All polls must be after June 28th.
I like to look up the results of the polls as they are released (realclearpolitics) but I have no idea which pollsters are approved and (if applicable) which of their polls count. I have attempted to google this but keep finding news articles explaining the information above instead of answering this question.