1. B. E. Blair, and W. I. Duvall , 1954 . Evaluation of gauges for measuring displacement, velocity and acceleration of seismic pulses , U.S. Bureau of Mines Report of Investigations, 5073 (Washington, U.S.A.).
2. Spherical Wave Propagation in Solid Media
3. W. I. Duvall, and T. C. Atchison , 1957 . Rock Breakage by explosives , U.S. Bureau of Mines Report of Investigations, 5356 (Washington, U.S.A.).