Ye.S. Avotina, Yu.A. Kolesnichenko, and J.M. van Ruitenbeek, Theory of oscillations in the STM conductance resulting from subsurface defects (Review Article), Low Temp. Phys. 36, (2010) [Fiz. Nizk. Temp. 36, 1066-1084, (2010)] DOI: https://doi.org/10.1063/1.3514417.