According to the Modern Language Association style guide, a works cited page has no minimum or maximum number of sources that must be included. However, any thoroughly researched article or paper necessarily has more than three works cited.
A works cited page differs from a bibliography because it includes all sources used for research and reference, not just those that are quoted from. As a result, it includes more than three works unless several references are made to a single comprehensive source such as an encyclopedia or anthology. If a paper has a very small number of sources, it may appear to be less well researched and less authoritative.