@InCollection{CRC_covar,
  author	= {F. Hlawatsch and G. Taub{\"o}ck},
  title		= {The covariance theory of time-frequency analysis},
  chapter	= {4.3},
  booktitle	= {Time-Frequency Signal Analysis and Processing: A Comprehensive Reference},
  year		= {2003},
  editor	= {B. Boashash},
  publisher	= {Elsevier},
  address	= {Oxford (UK)},
  pages		= {102--113}
}