Barrientos, Z., & Umaña, R. (2009). Student attrition in posgraduate blended programs at the Universidad Estatal a Distancia (UNED), Costa Rica: Desertion or delay?
Chicago Style aipamenaBarrientos, Zaidett, y Roy Umaña. Student Attrition in Posgraduate Blended Programs At the Universidad Estatal a Distancia (UNED), Costa Rica: Desertion or Delay? 2009.
MLA aipamenaBarrientos, Zaidett, y Roy Umaña. Student Attrition in Posgraduate Blended Programs At the Universidad Estatal a Distancia (UNED), Costa Rica: Desertion or Delay? 2009.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.