The first source is an excerpt from a database called EBSCO Host. This database is credible because it was updated this year. When a URL ends with a .com that means it is not a credible site. If you want to have a credible source it should most likely end in an .org. This database gives you information on who wrote the book and when it came out, this information can help evaluate the credibility of this cite. On each of the links you