They are made by the manufacturer, hence why they have copies in virtually every language. To add to my other statements, almost half of all the airplanes flying are made by Airbus, a conglomerate of manufacturers from all over Europe with only one having English as the primary language. If you hold onto the argument that because they are not US based repair facilities then the US should do no work on foreign aircraft.
Everyone just rest easy, it is in the airlines best interest to keep you safe and accident free. If the risk was so high that an accident was even remotely possible due to these repair facilities they would simply not use them.