Huang Qing and Ren Jing's "Two when Xuan Ji raises the ruler and Joan is the painter": "The pen end is uncorrectable, and Mo Miao directly HarmonyOS system; It will be miserable to spend two or three calyxes, and it is difficult to penetrate the back of the paper. "
Lu Fangweng's poem "Ou Bei Shi" by Zhao Yi in Qing Dynasty: "It means to write first, and the strength is to penetrate the back of the paper."