UPDATED: Nick Raven ans the S.A.T.AN. Squad

I've looked before (here) and (here) at the 'Adventure Knowledge' series featuring the art of Gerry 'Dan Dare' Embleton. I knew there were 4 books in the series:
a). Danger on the red planet
b). Death in the Arctic
c). Mystery of the pharaoh
d). Lost in the Amazon

So there's two books that I can't even find cover images for! 
Thanks to that other friend of the blog John Freeman I now have copies of the 2 book covers I was missing

...and John has also pointed out that the books were also published in Spain - link here 

So I was delighted that friend of the blog David Ronayne posted this image over the weekend - a bargain that he found at a local book fair...

…so that's a collected edition of all 4 books to look out for - if you come across Death in the Arctic or Mystery of the pharaoh please let me know as I'd love to see those covers.