• https://dspace.ucacue.edu.ec/items/0eb34f89-0c3c-484a-af63-2f3fa926c85c
• https://dspace.ucacue.edu.ec/items/014d7188-06b9-4324-921a-21901055f477
• https://dspace.ucacue.edu.ec/items/6f946eb0-4e68-4d16-bc7f-b12988fb0228