Makis Leontidis Constantine Halatsis Maria Grigoriadou e-Learning Issues under an Affective Perspective. 27-38 2008 ICWL http://dx.doi.org/10.1007/978-3-540-85033-5_4 conf/icwl/2008 db/conf/icwl/icwl2008.html#LeontidisHG08