@article{zhang2009semi,
  title={Semi-blind source extraction algorithm for fetal electrocardiogram based on generalized autocorrelations and reference signals},
  author={Zhang, Hongjuan and Shi, Zhenwei and Guo, Chonghui and Feng, Enmin},
  journal={Journal of computational and applied mathematics},
  volume={223},
  number={1},
  pages={409--420},
  year={2009},
  publisher={Elsevier}
}