Hi. You have not informed the source your question refers to. This makes it difficult for your question to be answered. However, I will try to help you as best I can.
There are some details you can analyze to find out if a research source is trustworthy or not. Among these details, the list of citations is one of the most efficient. This is because a reliable research source must present a citation list, which shows the places where that source was researched, which proves that all the information contained in it is true and proven by other works. In addition, you should note that the author of the research source is an expert on the subject that the research source addresses. This shows that the author has knowledge and is well versed in the subject he is presenting. Lastly, it is important to make sure that this research source is hosted on reputable sites. These trusted websites, which belong to respected and relevant institutions.