NOTE: there are some minor differences in names when translating from English to Spanish. Sharn(Gresh's planet in Space Olympics) becomes Sharm in Spanish, and Threefax(where you find Phatax) becomes Trefax. Also Dreefoid(life form in Robot World) becomes Drifoid.
These books are taken from the library, and some were covered in plastic, and some had tabs on the side, so that is why the covers may look a little strange. Still, I think we can see the important parts of the pictures.
Here are pictures of the first book, Find the Kirillian:
Front cover/Back cover/Introduction/An amusing ending, with graphics re-touched in Spanish
Here are pictures for the second book, The Galactic Pirate:
Front cover/Back cover/Codes in Spanish
The codes are "Fuego,"(fire) "Voltage" and "Peligro"(danger).
Here are pictures for the third book, Robot World:
Front cover/Back cover/Doctor Cyberg
Here are pictures for the fourth book, The Space Olympics:
Front cover/Back cover/"Airlock" in the top graphic/2-page picture still with English in the graphics.