Ariel Molina-Rueda Yazmín Magallanes-Velázquez J. Alfredo Sánchez Huitrón David Flores Enriquez Using heat maps for studying user preferences in vertical and horizontal multi-touch surfaces. 21-26 2013 CONIELECOMP https://doi.org/10.1109/CONIELECOMP.2013.6525751 conf/conielecomp/2013 db/conf/conielecomp/conielecomp2013.html#Molina-RuedaMHE13