on Just Publishing Advice
You can create a hyperlink to any web pages in your ebook to improve reading experience.
With so many types of e-reader devices and reading apps connected to wifi and the Internet, adding links to an ebook makes a lot of sense.
Whether your book reader chooses to use Kindle books, Apple iBooks, Kobo books or Kindle Unlimited, your HTML links will work.
If you publish with Smashwords or Draft2digital, you can add links that will work on all ebook reader devices and apps. For example, the Kindle app on an iPad or iPhone.
You can add links to anywhere you like. You can add reference sites, your blog articles, your other book titles or even a direct link to your email address.