The covers are different. One of them has the text "8 Edicion" and the other does not. From a cursory Internet search it seems like this text may actually appear on the cover.
Yes, that's true.. these editions are infinite and all the covers are the same except for that inscription, that's why I thought it was redundant, the isbn is the same too.. But I guess you could consider them alternate cover editions...
Indeed, ACE is exactly what they are. Goodreads policy is to keep all published covers on the site, as readers want to shelve the cover of the copy they have.
https://www.goodreads.com/book/show/4...
Thank youu!