This is not easy to answer More than  people worked on it generally speaking each one adding a sentence or changing some bit Each one must have used a different source of information  many must have simply used their own knowledge  However if there is a particular bit that look to you fishy thats much easier Go through the page history use the history button at the top and see when it was added and by whom Then ask that person People usually respond very nicely to such requests You might want to read the relevant policy verifiability