@inproceedings{perceptualfeedbackincomputerassisted,
  title = {Perceptual Feedback in Computer Assisted Pronunciation Training: A Survey},
  author = {Renlong Ai},
  year = {2013},
  booktitle = {RANLP 2013 9},
  url = {https://aclanthology.org/R13-2001},
}