Reference Sources provide quick answers to research questions. They are not meant to be read in full but are referred to on an as-needed basis. Examples of physical reference sources are dictionaries and encyclopedias. There are many free reference sources available online. One popular source is Wikipedia. Contrary to popular belief, Wikipedia is an edited source, usually with quite reliable information. However, Wikipedia's greatest assess are the References and Further Reading sections at the bottom of each article. These sections provide a great opportunity to find more research sources. In addition, the below reference sources are of particular use for psychology research: