• https://repositorio.uti.edu.ec/items/68aa8961-bc2e-4b2e-8d48-1fa773a27613
• https://repositorio.uti.edu.ec/items/a2294b45-e120-42ca-87eb-f2eed64421c8
• https://repositorio.uti.edu.ec/items/28e8d3dc-fcb1-449f-9683-9ca7d2ef55e3
• https://repositorio.uti.edu.ec/items/ed0491c8-36e8-4c62-b700-b1247efcd08c