The Secret of the Golden Flower
The Secret of the Golden Flower (Chinese: 太乙金華宗旨; pinyin: Tàiyǐ Jīnhuá Zōngzhǐ) is a Chinese Taoist traditional medical textbook on neidan (inner alchemy) meditation, which also mixes Buddhist teachings with some Confucian thoughts. It was written by means of the spirit-writing (fuji) technique, through two groups, in 1688 and 1692.
Source: Wikipedia — The Secret of the Golden Flower (CC BY-SA 4.0)