How to link your ebook to print, even if you don't use D2D print

According to store partners that carry both print and digital versions of books, they automatically attempt to link books based on these details:

If you have an ebook and a paperback of the same title, their detail pages should link automatically if the book details match. 

Please be aware that it can take some services a week, sometimes two, for the appropriate process to run that will link a paperback and digital version. Please allow newly published books time to correct on their own. If this connection doesn't happen automatically, reach out to your print vendor (KDP, Ingram, B&N, etc.) and provide them with both the print and digital ISBN to get them to link properly.