Meta: This endless "do you have sources" plays right into the hands of liars. If you don't have real reason to believe that some crucial fact may be missing you shouldn't invite them to spew their nonsense. If they had something real, they would have posted it the first time. Asking them just lets them draw the "I'm just answering an honest question" card, thereby making it seem that now there are two posters discussing the issue. A well-known trick.