• https://repository.upb.edu.co/items/452985cd-1c44-410f-941c-6e1d4115e991
• https://repository.upb.edu.co/items/7c4f5967-8c53-4f18-a641-d32f96e03ed6
• https://repository.upb.edu.co/items/15525015-14ed-458e-82d1-1493e7852c4f
• https://repository.upb.edu.co/items/409eb7cb-f036-4d22-a4bf-d63d9e21766c
• https://repository.upb.edu.co/items/9b1193c2-1755-439e-962d-3cd57a5d164a