Winter Holiday Danish 1959?
Publisher Thorkild Becks Forlag, CopenhagenTranslation by Kai Sørensen, cover illustrations by Axel Mathiesen
The original stories were unusually divided in two parts, each slim volume having no illustrations apart from those on the cover. The two titles mean "The Swallows on Winter Holiday" and "The Swallows' North Pole Expedition".
Robert's home page Ransome home page Winter Holiday Danish editions