Martin K. Beyer, Elena V. Savchenko, and Vladimir E. Bondybey, The contribution of tunnelling to the diffusion of protons and deuterons in rare gas solids: Low-Temperature Thermodynamics and Structure, Low Temp. Phys. 29, (2003) [Fiz. Nizk. Temp. 29, 1045-1048, (2003)] DOI: https://doi.org/10.1063/1.1614194.