Quizás, Quizás, Quizás soundtrack. Who is the singer?

Who is the singer on the soundtrack song "Quizás, Quizás, Quizás" (perhaps, perhaps, perhaps), the one played in the fishing scene? I know there are a lot of covers for this song, But I really like this version. The tempo is just right, not too fast or too slow. The song is not in the end credits nor in the OST. It is a female singer singing in Spanish and it is not the Laura Fygi vrtsion.