L. Vieira. Proceedings of the IX Brazilian Symposium on Computer Games and Digital Entertainment, page 244-247. Brazilian Computer Society, (November 2010)
J. Hernandez, M. Hoque, W. Drevo, and R. Picard. Proceedings of the 2012 ACM Conference on Ubiquitous Computing, page 301--310. New York, NY, USA, ACM, (2012)