Who is???

I have not seen this answered in the text, or on the forum. Can someone please tell me who "Plain Questions" is? They are liberally quoted in the text.
thanks,
Geezer
Maine, USA
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geezer

"Plain Questions" is not a person, it's the part of a book, it's the first half of "Yellow Emperor's Internal Classic".

For sure the book could be liberally quoted anywhere, for it is written thousands of years ago and the author keeps unknown.