@Conference{HlawatschTwaroch97a,
  author	= {F. Hlawatsch and T. Twaroch},
  title		= {Extending the characteristic function method for joint $a$-$b$ and time-frequency analysis},
  booktitle	= {Proc. IEEE ICASSP-97},
  year		= {1997},
  month		= {April},
  address	= {Munich, Germany},
  pages		= {2049--2052},
  volume	= {3}
}