Scaling of the Conductivity with Temperature and Uniaxial Stress in Si:B   at the Metal-Insulator Transition
  Using uniaxial stress to tune Si:B through the metal-insulator transition we find the conductivity at low temperatures shows an excellent fit to scaling with temperature and stress on both sides of the transition. The scaling functions yield the conductivity in the metallic and insulating phases, and allow a reliable determination of the temperature dependence in the critical regions on both sides of the transition. 
S. Bogdanovich, M. P. Sarachik, and R. N. Bhatt