I didn't quite know where to put this. It is not a book and I don't give it my personal recommendation. However, for information on the way the real Greek scholars (not folks like me) grapple with these issues it is very rich. This will explain 'textforms' and even tell you that...
There are in fact over 1500 places where the Textus Receptus differs from the Majority Text, some of them -- e.g. the placement of the Doxology of Romans -- quite significant).
I heard a great commentary on the subject that said this, 'my faith is not in Erasmus, nor the King James translators, nor any other man, but in God, and He is able to preserve His word.'Psalm 12:6 "The words of the LORD are pure words: as silver tried in a furnace of earth, purified seven times."Luke 21:33 "Heaven and earth shall pass away: but my words shall not pass away."