De Choudhury, M., M. Gamon, and S. Counts. “Happy, Nervous or Surprised? Classification of Human Affective States in Social Media”. Proceedings of the International AAAI Conference on Web and Social Media, vol. 6, no. 1, Aug. 2021, pp. 435-8, doi:10.1609/icwsm.v6i1.14335.