pguillem has hit on an interesting problem here.
Spanish is my third language, after English and Swedish, and I have always had a problem with the word "por".
There are two critical translations here, "for" and "by".
Personally, my translation would be "for" the "Hermanos Bolado" because of the context of the posting in the site I think all of us are referring to.
I am still Googling to find something on the "Familia Bolado" in Equatorial Guinea but with no success so far.
In any case, and without trying to be Politically Incorrect, the passengers were not native citizens of that country in my opinion and were the children of the then ruling Spaniards. I had the same experience living in Peru, where there was the "English
School", the "American School", the "German School" and so forth where in that case the ExPats sent their children to schools more aligned with their home country.
I think the point is well awarded, but perhaps we need a few more details.
Bill