Exporting highlights from Kindle Personal Documents to a TXT file

There are two main categories in Kindle App for iPad: - Books - contains books purchased from Amazon; highlights are available at https://kindle.amazon.com/your_highlights — it works fine for me. - Personal Documents - contains all other books; highlights are not available online. So, I have book purchased at different source than Amazon and I would like to be able to export my highlights and notes to a text file (or any other common format). My approaches so far: - As far as I know, https://kindle.amazon.com/your_highlights is available for Books category and thus, for Amazon-purchased books only. There are no entries from "Personal Documents" - I cannot move my book from Personal Document to Books - there is no such option in Kindle App. There is no such option on Amazon's "Manage Your Kindle" site too. - There is no option to export all highlights. Kindle app has option to share a highlight via Facebook or Twitter, but there is no option for copy or export it. I synced my book with Kindle Touch and highlights are synced successfully. But: - There is no export option in Kindle Touch too. - I am unable to read highlights content on my cpu. The file with highlights has extension .azw3r and contains relative references, for example: annotation.personal.highlight 283390 283606. - There are no entries in My Clippings text file (there are entries there but for non-synced books). The question is: **How can I export my highlights and notes from iPad Kindle App to a TXT or any other common file?** *Note I'm using Windows but I put this question to Apple.SE since the root problem comes from iPad.*