Audiobook separated into 2 parts with 2 ISBNs - merge or not?

[Regan]

While combining editions for The Big Rock Candy Mountain I noticed that one edition, an audio cassette edition, was split into two parts. This was just that the cassettes had been packaged into two boxes; this book has not been issued as two separate parts, so I set about merging them.

However, it turns out that the two boxes have two separate ISBNs.

Should these two things be merged into a single edition or not?

[rivka, Former Moderator]

A book that has been split into two parts -- audio, e-, print, whatever -- is NOT combined with versions of the book with one part. Nor are the two parts combined with each other.

[Regan]

Most audio books have multiple parts, but are not considered separate books. So I'm not clear on what the criteria are for "parts being separate books." Is it because they have separate ISBNs?

This is not one of those books, like say Lord of the Rings or The Once and Future King or The Forsyte Saga that are sometimes published as single books and sometimes as their individual component parts. This is more like publishing two halves of the dictionary in two paperbacks.

[rivka, Former Moderator]

Separate ISBNs means they were published/released separately. That's quite different than an audiobook made up of two cassettes but sold as one item.

[Regan]

Gotcha. Thanks for the assist.