How can you determine if a source is credible

You go to other sources and you see if most of them have the same information. Hope this helps :)

You can determine if a source is credible by checking if the date it was made is near the present date, checking for no spelling errors, and how the person wrote it. if the person used alot of slang words, the source is probably just an opinion if it is online. Usually most books are credible because they got published.