Telmo Zarraonandia Paloma Díaz Esther Guerra Mario Rafael Ruiz Vargas Ignacio Aedo A Framework for the Multi-disciplinary Design of Web-Based Educational Systems. 45-49 2009 ICALT http://dx.doi.org/10.1109/ICALT.2009.121 conf/icalt/2009 db/conf/icalt/icalt2009.html#ZarraonandiaDGVA09