Unless there is any contract between you to say otherwise, the copyright would be shared and you would be entitled to any royalties jointly. He can't revise it and take your name off it as your efforts were still involved with the production of the work. You are both entitled to exploit the work but you should both be sharing the royalties. If you can't reach an agreement your remedy would be take him to court to ask the court to make him account for the royalties and pay you your share. I hope that helps. Please leave a positive rating so that I am credited for my time.