It is now possible to search the entire corpus of the Works of Jonathan Edwards online. This is thanks to Yale University. You have to create an account, but it's free. This is all especially helpful in light of the price of the 24 printed copies.
As you punch in words, you get a link to the piece in which it is found, including the year it was written and the total number of words in that piece--whether it's short (a miscellany), medium (a sermon), or long (a treatise). 47 matching documents on "regeneration" just about made my blood boil. You can also search by Scripture text, which is especially valuable (particularly for preachers) since almost no JE works have included Scripture indeces.