TY - JOUR AU - Penn, David AU - Girvin, S AU - Mahan, G C2 - Physical Review B (Condensed Matter and Materials Physics) DA - 1981-12-15 00:12:00 LA - en M1 - 24 PB - Physical Review B (Condensed Matter and Materials Physics) PY - 1981 TI - Dispersion Relation Approach to the X-Ray Edge Problem ER -