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 "Reference icon", or the icon (and name) for the template that was used to create this reference. Clicking the "Edit" button opens a "template mini-editor" dialog where you can edit the information for that reference.
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), select it in the left column.
When you're done editing the reference, click "Apply changes". Remember, you'll still need to then save your changes!