1. The basic form of the codex was invented in Pergamon in the third century B.C.E. or had earlier forms. The fourth century B.C.E. was the age of its popularity.
2. An obvious error is the two Chinese characters should be carved reversely.
Also, in Song Dynasty, In the Song Dynasty, they should be traditional Chinese characters rather than simplified ones.
3. Traditionally, paper is thought to have been invented in the early 2nd century B.C., but there is evidence that it was much earlier, around the time of the Western Han Dynasty in China. Its invention may have been accidental, and its rough texture prevents it from being widely produced, used and disseminated. In the Eastern Han Dynasty, Cai Lun improved papermaking. This was one of the pinnacles of Chinese ideology and culture, when the improved paper was introduced to the West as a commodity and other mediums along the silk road.
Sources:
https://www.newworldencyclopedia.org/entry/Codex
Video 3, “Moveable Wooden Type – developed in China. This documentary shows how this works even today.“
https://www.ancient.eu/article/1120/paper-in-ancient-china/
