《北史·列传·卷六十》
至于阴阳、《河》、《洛》之类的书籍，医书图谱著作，更加少了。
至于阴阳《河洛》之篇，医方图谱之说，弥复为少。
As for the books of yin-yang, the books of the Yellow River and the Luo River, the medical books and the illustrated books, they are even more lacking.