• https://repositorio.upn.edu.pe/items/5bc3ef29-a0d6-4734-bd4e-54011677f4e0
• https://repositorio.upn.edu.pe/items/a44640d6-c853-4a96-993c-524a3d9d4c0f
• https://repositorio.upn.edu.pe/items/03844d3d-2004-4509-9470-f86e37e139d8
• https://repositorio.upn.edu.pe/items/2d31ab43-cdcf-429e-9cfc-0931add7de57
• https://repositorio.upn.edu.pe/items/3c85ce76-6cc5-403d-92cc-4de46d64ec6f