1. Kratz, K.O., Gerling, E.K. and Loback-Zhuchencko, S. 1968, Can. J, Earth Sci., 5, pp 657–660.
2. O’Nions, R.K., Morton, R.D. and Baadsgaard, H. 1969, Nor. Geol. Tidsskr. 49, pp 171–190.
3. Lundqvist, T. 1979, Sver. Geol. Unders. 758, pp 1–87.
4. Magnusson, N.H. 1969, Geol, Fören, Stockholm. Forh. 82, pp 407–432.
5. Barth, T.F.W. and Dons. J.A. 1969, In “Geology of Norway” (O. Holtedahl, Ed.), Nor. Geol. Unders. 208, pp 6–67.