You may quickly check all the formats for a title that you've published on KDP by linking your books on your KDP Bookshelf. When you publish the same book in different forms (such as an eBook, paperback, or hardcover edition), Amazon will attempt to link them all together into a single product information page.
By following these steps, you can link your own books to your KDP Bookshelf for your Book, paperback, or hardcover versions:
Books can be unlinked on Amazon and on your KDP Bookshelf.
On the Amazon details page a book can only be unlinked if it is linked to an incorrect book. Books in the public domain cannot be separated from other public domain books that share the same metadata.
To unlink a book on the Amazon details page, you will have to contact them and give them the ASIN of the eBook and the 10-digit ISBN number of the hardcover or paperback.
To unlink your book from your bookshelf (not your Amazon details page):