# Reference Other Sources

![Power a Page](https://github.com/stoplightio/docs/blob/develop/assets/gifs/hubs-power-page.gif?raw=true)

## What
Hubs allows you to reference other sources to automatically populate your Hub with content. We call this “powering” a page, subpage, or block. You can power a page, subpage, or block with a markdown or specification file from the current file, a file from the current project, a file from another project, or a file from an external source. 

### What Can I Power

- Pages 
- Subpages 
- Blocks 

## How

### Power a Subpage 

1. Select the Hub you wish to modify 
2. Select **Design** view
3. Click on **Page Settings & TOC** at the top of the page
    1. Select the **page** or **subpage** you wish to power
    2. Under Page Type, select **Markdown**(for markdown files) or **OpenAPI** (for JSON or YAML files)
    3. Input the specific data source or select from the drop-down menu
    4. Input an inner data source (optional)  
4. Click **Confirm**  

>Try it Out! Power a Subpage with an API Spec from the same project.

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**Related Articles**
- [Documentation with Hubs](/documentation/introduction)
- [Routing](/documentation/getting-started/routing)
- [Headers & Footers](/documentation/getting-started/header-footer)
- [Pages](/documentation/getting-started/pages)
- [Subpages](/documentation/getting-started/subpages)
- [Blocks](/documentation/blocks)
