Huangdi Neijing
First, Huangdi Neijing is the first classic of TCM theory.
Second, Huangdi Neijing is the first book of health preservation.
Thirdly, Huangdi Neijing is the first encyclopedia about life.
Most importantly, there is nothing like Zhang Wuben in this book, and almost no one can deny its authenticity. This is a book that you can't tell the truth of TCM health preservation today. Remember to buy the original popular version.
I wish you and your family good health!