1. Allen, J.R.L. (1986): Pedogenic calcretes in the Old Red Sandstone facies (Late Silurian-Early Carboniferous) of the Anglo-Welsh area, Southern Britain.-In: Wright, V.P. (ed.) Paleosols-Their Recognition and Interpretation, 58–86. Oxford.
2. Allen, K.C. (1965): Lower and Middle Devonian Spores of North and Central Vestspitsbergen.— Palaeontology 8/4, 687–748.
3. Allen, K.C. (1967): Spore assemblages and their stratigraphical application in the Lower and Middle Devonian of north and central Vestspitsbergen.— Palaeontology 10/2, 280–297.
4. Allen, K.C. (1973): Further information on the Lower and Middle Devonian spores from Dickson Land. Spitsbergen.— Norsk Polarinstitutt Årbok 1971, 43–54.
5. Astin, T.R. (1990): The Devonian lacustrine sediments of Orkney, Scotland; implications for climate cyclicity, basin structure and maturation history.— Journal of the Geological Society London 147, 141–151.