The word "multiple" is not a set number and depends on the type of organization or product. Editors should recognize certain biases, such as [[Wikipedia:Recentism|recentism]] (greater availability of recent sources) when assessing historical companies or [[Wikipedia:Systemic bias|systemic bias]] (greater availability of English and Western sources) when discussing organizations in the developing world. Therefore, for example, a Bangladeshi women's rights organization from the 1960s might establish notability with just one or two quality sources, while the same is not true for a tech start-up in a major U.S. metropolitan area.
Reliable sources, generally, are third-party published sources with a reputation for fact-checking and accuracy. The best sources have a professional structure in place for checking or analyzing facts, legal issues, evidence, and arguments. The greater the degree of scrutiny given to these issues, the more reliable the source. Questionable sources are those that have a poor reputation for checking the facts, lack meaningful editorial oversight, or have an apparent conflict of interest. Self-published sources are generally not accepted as reliable sources. For a full discussion on what is and what is not a reliable source, see [[Wikipedia:Identifying reliable sources]].