energy velocity

Comment on “The Problem of Light Diffusion in Strongly Scattering Media
B. A. van Tiggelen, A. Lagendijk, and A. Tip
Phys. Rev. Lett. 71, 1284 (1993)

Speed of propagation of classical waves in strongly scattering media
M. P. van Albada, B. A. van Tiggelen, A. Lagendijk, and A. Tip
Phys. Rev. Lett. 66, 3132-3135 (1991)