@book{ HASSAN_ORTEGA:73,

author = { YUSEF HASSAN MONTERO and SERGIO ORTEGA SANTAMARÍA } ,

title = { INFORME APEI SOBRE USABILIDAD },

publisher = { APEI },

address = { GIJÓN, ESPAÑA },

year = { 2009 },

pages = { 73 },

isbn = { 978-84-692-37 },

}