• https://repositorio.untumbes.edu.pe/items/af3b9867-1d90-46af-82c9-ec73cde32a26
• https://repositorio.untumbes.edu.pe/items/3a939b96-37ea-400c-8eae-f8747561c136
• https://repositorio.untumbes.edu.pe/items/26f9925d-8e5f-4794-ad1d-3a26d904a976
• https://repositorio.untumbes.edu.pe/items/cee4d1ad-2094-443d-97b4-d7d6cedcfa9a
• https://repositorio.untumbes.edu.pe/items/5313659e-6cbf-4281-9af6-9bafceee6c09