Books with Two ISBNs

[Aibohphobia]

I have a couple of books that have two ISBNs. They were published in a collaboration between a US publisher and a UK publisher, so it's the same book, but with one US ISBN and one UK ISBN.

These books are already in Goodreads as different editions of the same book, so should they be left like that, or combined? (Or some other option I haven't thought of?)

1. Green and Pleasant Land:

US ISBN 0933635397
https://www.goodreads.com/book/show/2...

UK ISBN 1869893069
https://www.goodreads.com/book/show/1...

2. Call of Cthulhu (3rd Edition):

US ISBN 093363515X
https://www.goodreads.com/book/show/3...

UK ISBN 086989300X
https://www.goodreads.com/book/show/1...

[Abcdarian]

I'm pretty sure if the ISBNs are different, both editions stay. They are already combined, in that the editions are linked. Merging would mean one edition would get deleted, which would be wrong since different people could have it shelved under different ISBNs. QED, they stay the way they are. :-)

[Aibohphobia]

That's pretty much what I thought, but I wanted to err on the side of asking. Maybe just a note in the description explaining that they're the same?