Kindle App Problems!

[iMore Question]

There are documents that are only showing up on my iPad4 kindle app and are not accessible through my amazon kindle library or cloud. The documents are PDF files that I purchased from non-amazon websites and downloaded them to the iPad4 via the safari web browser option to "open in kindle app." At the time, I did not have a computer to back-up files and I assumed the files would be accessible through amazon cloud on my other devices (kindle paperwhite and iphone4s). Unfortunately that is not the case. I am selling my iPad4 and need my PDF files. How do I extract them from the kindle app and save them to my computer?

 

[kch50428]

Can you get them from the original source again?