Please add this cover.

[Mike]

https://www.goodreads.com/book/show/1...

With ISBN unknown unfortunately but with ASIN
B00525FA1W.

https://www.abebooks.com/servlet/Book...

[Martin]

Goodreads listing is 1966 edition, your source is 1976 edition.

[Mike]

Martin wrote: "Goodreads listing is 1966 edition, your source is 1976 edition."

No idea about that, could one of them have an incorrect date or there are more editions that Goodreads doesn't include?

[Martin]

Maybe.
If the date is incorrect on Goodreads you could submit a request for correction at 'book & author page issues'.
If your source is incorrect you could look for one which is correct and acceptable, then submit a further cover request.
If they are different editions you could request a further edition at 'adding new books & editions'.