Investigations of Carboniferous and Permian sediments in Svalbard : [Pt.1: The development of the Gipshuken Formation (Lower Permian) at Trollfuglfjella in Central Spitsbergen, Svalbard ] ; [Pt. 2: The Carboniferous and Permian stratigraphy of the Wahlenbergfjorden area, Nordaustlandet, Svalbard] [82-90307-17-9] Lauritzen, Ørnulf