@inproceedings{smileandlaughterinhumanmachine,
  title = {Smile and Laughter in Human-Machine Interaction: a study of engagement},
  author = {Mariette Soury and Laurence Devillers},
  year = {2014},
  booktitle = {LREC 2014 5},
  url = {https://aclanthology.org/L14-1718},
}