 | This is an essay on notability. It contains the advice or opinions of one or more Wikipedia contributors. This page is not an encyclopedia article, nor is it one of Wikipedia's policies or guidelines, as it has not been thoroughly vetted by the community. Some essays represent widespread norms; others only represent minority viewpoints. |
 | This page in a nutshell: Three suitable sources is the standard most often used to determine notability, though this may vary case by case. |
Wikipedia's general notability guideline states that "no fixed number of sources [are] required .... but multiple sources are generally expected" in order to establish notability. The word multiple is purposely left vague in the guideline because "sources vary in quality and depth of coverage".
Although in the strictest sense the word "multiple" means "more than one", and in some cases it may indeed be possible to establish notability with only two references, based on existing Wikipedia community norms, challenges to notability are more often successfully rebuffed when there are three good in-depth references in reliable, secondary sources that are independent of each other and of the subject. It is important to note that the quality of any reference can always be challenged. A successful challenge would, of course, reduce the number of "good in-depth references". It's a good idea to check the list of "perennial sources" to see if a source is listed as "deprecated", "banned", or otherwise found to be unreliable by the Wikipedia community.
When considering the quality of the sources, it is helpful, but not mandatory, if the authors and/or publications of the references are notable and have Wikipedia articles. Of course, if the author is notable for being a prankster, or the publication is notable as a tabloid, this reduces the quality of the reference.