《北史·列传·卷二十六》
再加上内地人和边人不断交错，疆域不断变动，西部的戎族和北部的狄族说话又不一样，事情很难弄清楚。
兼复部人交错，封疆移改，戎狄音殊，事难穷验。
Furthermore, the boundary between the inlanders and frontiersmen always changed, and the spoken languages of the Rong tribe in West and the Di tribes in the north were also different. The situation was extremely complicated.