Purchased book won't transfer to new iPad

I bought an iPad Air and thought my purchased books would transfer from my iPad2 by doing a backup to iTunes on my Dell PC, and then restoring to my iPad Air. They did not. I then selected the store button on the iBooks bookcase on my iPad Air and was taken to the iBooks store. I selected purchased books and saw all my purchased books there. I clicked the cloud symbol on each book which then brought up an UPDATE symbol. I touched the UPDATE symbol for each book and they all updated except one. My Holy Bible NIV said it was no longer available for purchase. I presume that means it is no longer available for update. Anyway, the book shows in my bookcase, but when I touch it, I get an error message stating: "Requested resource is missing." I can read the Bible on my old iPad (which I want to retire), but I can't access it on my new iPad. It doesn't seem right. Isn't there anyway to transfer it from the old to the new?