《北史·列传·卷三十》
我认为，自周朝以上，学校只有两处，或者在东面，或者在西面；或者在城内，或者在城外。
臣案：自周已上，学唯以二，或尚东，或尚西，或贵在国，或贵在郊。
I think that since the Zhou Dynasty, there have been only two schools, either in the east or in the west; either in the city or outside the city.