Perry, Walter <br/><br/>
The state of distance-learning worldwide :  the first report on the index of institutions involved in distance-learning / 
Perry Walter 
 - Reino Unido :  International Centre for DistanceLearning of the United Nations University 
 - p. 3-20 
<br/><br/> Fotocopia 
<br/><br/><label>Encabezamiento--Tema: </label><br/>Educación a distancia