TY - JOUR AU - Liu, W AU - Clark, Charles C2 - Physical Review A (Atomic, Molecular and Optical Physics) DA - 1996-01-01 00:01:00 LA - en M1 - 53 PB - Physical Review A (Atomic, Molecular and Optical Physics) PY - 1996 TI - Intensity-Dependence of the Phase of Harmonics in One- and Two-Frequency Laser Fields ER -