1. Jian-Zheng L, Zheng Z (2011) Head movement recognition based on LK algorithm and Gentleboost. In: Proceedings of 7th international conference on networked computing advanced information management, June, 2011, pp 232–236
2. Wöhler N-C (2010) A calibration-free head gesture recognition system with online capability. In: International conference on pattern recognition. doi: 10.1109/ICPR.2010.929
3. Saikia P, Das K (2013) Head gesture recognition using optical flow based classification with reinforcement of GMM based background subtraction. Int J Comput Appl (0975–8887), Volume 65, No. 25, March 2013
4. Burton A, Radford J (1978) Thinking in perspective: critical essays in the study of thought processes. Routledge. ISBN 0-416-85840-6
5. Agrawal A, Raj R, Porwal S (2013) Vision based multimodal human computer interaction using hand and head gestures. In: Proceedings of IEEE conference on information and communication technologies