@Article{GM-evolut,
  author	= {G. Matz and F. Hlawatsch and W. Kozek},
  title		= {Generalized evolutionary spectral analysis and the {W}eyl spectrum of nonstationary random processes},
  journal	= {IEEE Trans. Signal Processing},
  year		= {1997},
  month		= {June},
  volume	= {45},
  number	= {6},
  pages		= {1520--1534}
}