• https://repositorio.upse.edu.ec/items/6f98fa58-8013-4dde-8fc8-a969cd513e11
• https://repositorio.upse.edu.ec/items/24ad4d4c-1857-40ec-9a04-efea63225cd7
• https://repositorio.upse.edu.ec/items/cd2b1403-547e-4091-a936-49acbd8fa020
• https://repositorio.upse.edu.ec/items/42fd2b01-f9c5-47d0-9cf5-8fefd526fa04
• https://repositorio.upse.edu.ec/items/8b14fdef-9074-4c17-afd9-e47ec1be75fe
• https://repositorio.upse.edu.ec/items/aa360b4b-3065-4415-93cf-80424af9594f