https://www.gestionar-facil.com/como-calcular-el-costo-de-una-campana-publicitaria/
https://www.banamex.com/pymes/seguridad/auto-empresarial.html

vídeos del tema:
https://www.youtube.com/watch?v=s3DUFV8riIw
https://www.youtube.com/watch?v=8DeriR4eFMI
https://www.youtube.com/watch?v=tFmQllT-uW4