Multiple listings for a book in core

I realize that there may be multiple versions of a book ie. Hardcover, Paperback,etc and most these have different ISBNs, but it seems like there are a lot of books that are just duplicated with no real difference, so if I have to enter a book by title and author, I get a list to choose from and I have no idea which is the correct one. Example; Rescue Run Anne McCaffrey has five entries with no visible difference.
Is there any way to fix this?

If you don’t have an ISBN, and you search by author/title and get multiple results, just add the result that you like best. You can later edit the book to add all your own details for your own book.

It is not a problem if the one you choose is “not actually the one you have” - or perhaps some of them are double in Core.

There’s not really a “fix” - but you can solve this easily by just picking one, then modifying it to your liking.

In any case, there are no duplicate ISBNs in Core.
So if you see multiple entries for the same book, they must be listed without ISBN, or with different ISBNs.

I understand there are no duplicate ISBNs, I was talking about the books without ISBNs. A large number of the books I have are Science Fiction Book Club edition which were issued pre 1970 so did not have an ISBN assigned. Are you aware of any online list of SFBC with ISBNs?