Balstrøm, T. (1986). Groundwater as a geometric agent: proceedings of the 13th Annual Geomorphology Symposium, held at Rensselaer Polytechnic Institute, Sept. 1982fed. by R.G. LaFleur. - (Binghamton symposia in geomorphology;l3). Geografisk Tidsskrift, 86. Hentet fra https://tidsskrift.dk/geografisktidsskrift/article/view/44386