What you say is very correct, of course we don't need to read books whose authors don't have clear reference sources because this will make it difficult for us to invest in Bitcoin and if we choose to read a book we have to first find out the background of the author, whether it is true. Whether an author has clear references or not, some people who make videos sometimes just take advantage for themselves and don't care whether what they say is in accordance with existing reality or not.
When someone finds out that the book they are reading contains wrong understanding, of course they will never read the book again and will look for a book that has an explanation and a clear reference source.
People read books to broaden their horizons so that they know more about the contents, but if the author cannot present accurate information, how can we possibly make comparisons about the writing that has been written? It is important to first look at the author's background because if you follow it incorrectly it will give a misleading understanding and even if the intention is to read then there must be a filter to filter the information contained in the book.
Now there are many videos and book made that are not about the content but rather trying to narrate something and they try to make a profit with these videos. Therefore, we have to be smart in choosing the reading and video we watch because if it is wrong it will give a wrong understanding.