Michalis Vrigkas, Vasileios Karavasilis, Christophoros Nikou, Ioannis A. Kakadiaris. Action Recognition by Matching Clustered Trajectories of Motion Vectors. In Sebastiano Battiato, José Braz, editors, VISAPP 2013 - Proceedings of the International Conference on Computer Vision Theory and Applications, Volume 1, Barcelona, Spain, 21-24 February, 2013. pages 112-117, SciTePress, 2013.