WP:External links

Articles may include external links, links to web pages outside Wikipedia. External links normally should not be placed in the body of an article. All external links must conform to certain formatting restrictions.

Some acceptable external links include those that contain further research that is accurate and on-topic, information that could not be added to the article for reasons such as copyright or amount of detail, or other meaningful, relevant content that is not suitable for inclusion in an article for reasons unrelated to its accuracy.