1. The measurement of stress in rock—Part II: Borehole rock stress measuring instruments;Leeman;Jl. S. Afr. Inst. Min. Metall.,1964
2. Borehole Deformation Gage for Determining the Stress in Mine Rocks;Obert;U.S. Bureau of Mines Report of Investigation 5978,1962
3. Deformation of the Borehole in Rock;Merrill;U.S. Bureau of Mines Report of Investigation 5881,1961
4. The measurement of stress in rock—Part I: The principles of rock stress measurements;Leeman;Jl. S. Afr. Inst. Min. Metall.,1964