Fernando Zacarías Rosalba Cuapa Francisco Lozano Andres F. Andres Dionicio Zacarías u-Teacher: Ubiquitous Learning Approach. 9-20 2008 Edutainment http://dx.doi.org/10.1007/978-3-540-69736-7_2 conf/edutainment/2008 db/conf/edutainment/edutainment2008.html#ZacariasCLAZ08