"The Book of Hiding Armor" comes from the sixty-eighth chapter of Romance of the Three Kingdoms. Cao Cao asked Zuo Ci, "What magic can you do?" Zuo Ci replied: "I have been practicing in Emei Mountain all the year round. Suddenly, Lei Zhen has a broken stone wall, revealing three volumes of heavenly books, which are divided into three volumes: heaven, earth and man."
Although The Romance of the Three Kingdoms is based on history, it has actually added many legends of ghosts and gods, so there are many fictional elements, which come from history and are higher than history. Therefore, whether there is a "Dunjia gobbledygook" is still unknown and there is no clear textual research. In some current games and novels, Zuo Ci and "Dunjia Tianshu" are both portrayed as fantastic.
So I think the explanation in Baidu Encyclopedia is incorrect. Qingnangshu is recorded in history, but Dunga gobbledygook is not.