STAMP, P. C. E., & ZHANG, C. (1991). THEORY OF BLOCH DELOCALIZATION AND QUANTUM DIFFUSION OF HEAVY-PARTICLES IN INSULATORS. PHYSICAL REVIEW LETTERS, 66(14), 1902-1905. doi:10.1103/PhysRevLett.66.1902
STAMP, P. C. E., & ZHANG, C. (1991). THEORY OF BLOCH DELOCALIZATION AND QUANTUM DIFFUSION OF HEAVY-PARTICLES IN INSULATORS. PHYSICAL REVIEW LETTERS, 66(14), 1902-1905. doi:10.1103/PhysRevLett.66.1902