Help:Introduction to referencing with VisualEditor/3
Verifiability
Why references are important
Adding references
Automatically or manually
Editing existing ones
Always room for improvement
Reusing references
Some are just really useful
Reliable sources
Which sources are good enough?
Summary
Review of what you've learned
To edit an existing reference, click on the [number] where it appears in the text. You will see either a 
icon, or the icon (and name) for the template that was used to create this reference. Clicking on this icon will open a "template mini-editor" dialog where you can edit the information for that reference.
If, instead of the icon, what appears when you click on a reference, is an icon for a standard template for citations, clicking on that icon will take you directly to the template mini-editor dialog.
Inside the template mini-editor, you change the information in fields by typing in the boxes.
To add a new piece of information (for example, the publication date), click on "Edit", which is at the very bottom of the mini-editor.
When you're done editing the reference, click "Apply changes". Remember, you'll still need to then save your changes!
