Unknown song

[Cesar-ATR]

Hello.
Can anyone recognize this song, I heard it by chance in a documentary of the 80's and it caught my attention.
I tried to remove the narrator's voice so that more of the song could be heard.

https://u.pcloud.link/publink/show?code=XZ9sJiVZc0IEj8tiKCzox5hhqYa60ypdUDGk