1. R. Böker, Tests to correlate the failure envelops of wrapping tests and uniaxial compression tests (in German), Dissertation, Technical University, Aachen, 1914.
2. The mechanics of plastic deformation in crystalline solids (in German);Böker;Ver. dtsch. Ing. Mitt. Forsch,1915
3. S.A.F. Murrell, A criterion for brittle fracture of rocks and concrete under triaxial stress and the effect of pore pressure on the criterion, in: C. Fairhurst (Ed.), Rock Mechanics (Proc. 5th Symp. on Rock Mechanics, The University of Minnesota, 1962), Pergamon Press, New York, 1963, 563-577.
4. K. Mogi, Effect of the intermediate principal stress on rock failure, Journal of Geophysical Research 72 (1967) 5117-5131.
5. T. Kármán, Strength under pressure (in German), Z. Ver. dtsch. Ing. 55 (42) (1911) 1749-1757.