Using TinyMCE

1. Click the Article button.
   
2. Select your article.
3. The article will be inserted. 
4. Joomla will automatically match the text of the URL with the article title. 

Using JCE

1. Click Insert Link.
   
2. In Link Browser expand Content.
3. Expand the Category the article is located in.
4. Select the article which will fill the URL.
5. Enter text for this link and click on Insert.