Einstein, H.H., Bischoff, N., and Hofmann, E. (1972). Verhalten von Stollensohlen in quellendem Mergel (Behavior of invert slabs in swelling shale). In: Proceedings of International Symposium on Underground Openings (Grob, H., Kovári, K., eds.), September 1972, Lucerne, Switzerland, pp. 296–319. Published by the Swiss Society for Soil Mechanics and Foundation Engineering, Zurich, Switzerland.