Skeleton Men of Jupiter

This marks the completion of Edgar Rice Burroughs' John Carter of Mars (Barsoom) 12-book series. I have now read more books by him than any other author. Thus, will not return to Burroughs other books for many years to come. Nevertheless, still wholly recommend them.
As for a review of this John Carter of Mars series, I would say only the first book is absolutely necessary. They are all incredibly similar action adventure books. They are certainly fun, but not the conceptual and exploratory science fiction I am looking for.