8Cara M. Time - frequency analysis[ J ]. Eos, Transactions, American Geophysical Union, 1982,63 ( 51 ):13～20.
9Utsu- Tokuji. On the nature of three Alaskan after shock sequences of 1957 and 1958[J ]. Bulletin of the Seismological Society of America, 1962,52 (2): 279 ～ 297.
10Chant I J, Hastie L M. Time- frequency analysis of magnet- telluric data[J]. Geophysical Journal Intenational, 1992,111(2) :399～413.
