A brief introduction to ancient books that are difficult to interpret.

Medical classic "Difficult to Interpret". Two volumes. Written by Qing Xu Da Chun at 1727. Xu's annotation on Difficult Classics is based on the theory of Neijing, which has important reference value for explaining the meaning and academic origin of Difficult Classics. However, the author thinks that the view that "difficult classics must not violate Neijing" is somewhat extreme. Zhejiang Science and Technology Publishing House has various printed editions and 1985 printed editions.