Danish Superman # 14 from 1951 with Batman and Røde Pil (Red Arrow). Super rare. This book includes "Prankster's Second Childhood", one of the infamous stories Fredric Wertham emphasized as especially damaging to kids in 'The Seduction of the Innocent' (1954) because of a panel where one of the Prankster's goons shoots a police officer in the face (with what looks like a harmless water pistol).
The Danish Superman comics from 1950-52 are undoubtedly the most difficult Danish superhero comics to find. These early issues are extremely fragile, printed on thin paper with the cover being printed on the same stock as the inside pages. They were printed with red as the only color except for some splash pages (which is why Green Arrow ended up being called Røde Pil/Red Arrow in Danish). They also include the earliest appearances of Batman, Superboy and Green Arrow in Denmark.
These issues also had very unique, locally drawn covers, which for the most part were only published in Denmark, though the theory is that they were most likely produced at the publisher's headquarters in Sweden, although this has never been finally documented. Notice how the cover drawing is swiped from a panel inside.