We have applied Lifshitz-Kosevich theory to directly fit the high field osc
illatory magnetoresistance in the Q-1-dimensional Bechgaard salts in (TMTSF
)(2)X (X = AsF6 or ClO4[Q-state]) in their spin density wave states. Values
of m* Dingle temperature, and SdH frequencies are obtained, and the anomal
ous temperature dependence of the oscillation amplitudes are discussed.