Materials and references as the subject matter are sometimes also taken from the basic websites that have been trusted. Like, basic information from a work Book and the character of the previous author has been put and the rate at Goodreads

And for all types of Movies are generally in general, basic information such as directors, artist and actor profiles, Production houses and all kinds are taken from the most reliable in Imdb

and lastly, do not forget also on the presence of Wikipedia as an online encyclopedia is very meritorious to collect a variety of basic information and even universal.