Rules for combining box set editions

[Alissa]

I've combined together all the box set editions of a trilogy, but now I wonder if I did the correct thing, the titles are slightly different because I combined both the UK and the US versions, paperback and ebooks.

I did it because they are all different editions of the same work, but is it correct to combine the bundled ebook of a trilogy (not an omnibus but indeed three different ebooks bundled into one) with a three-book-box-set edition of the same trilogy?

Thank you.

[rivka, Former Moderator]

Yes.

[Alissa]

Thank you!