The post I made was an excerpt from one of my books and you are correct in pointing out that it failed to reference any studies or other sources.
When I originally saved the information I had not planned on including it in either an article or a book and so did not save the references that I checked out to validate the information - not the only time that has happened, since my research originally was for my own information and only later did I realize that I could share it in the form of articles and books.
However, I almost never take anything at face value and simply include it in a book, article or post without satisfying myself that the information is correct.
This more in-depth article does a better job of providing references: