A Brief History of Time - 2 versions, disambiguation notice?

Does anyone know what the difference between these two works is?
https://www.librarything.com/work/28593215
https://www.librarything.com/work/6431\
There does not seem to be a disambiguation notice, and that would be nice to have if anyone know the difference.

>1 al.vick: I think they should be combined...

Technically the 1996 version and most editions since then is an expanded version of the 1988 one but separating them will be a pain. These two contain mixes of both from a quick look.

If we can identify the pre-1996 editions, we can pull them out separately but it won't be easy or trivial

I would be in favor of combining them. I would also be in favor of pulling out the pre-1996 editions with a disambiguation note, but I don't know that I am the person for that job.