TY - JOUR AU - V. B. Bobrov TI - Exact relation for photon distribution function in a~medium in the long-wavelength limit JO - Teoretičeskaâ i matematičeskaâ fizika PY - 1991 SP - 141 EP - 145 VL - 88 IS - 1 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/TMF_1991_88_1_a17/ LA - ru ID - TMF_1991_88_1_a17 ER -