Within Teamwork.com, you can download a copy of a notebook in HTML or PDF format.
Go to the Notebooks area of your project and select the notebook you want to download.
In the notebook details view, click the Versions button in the top right and select the relevant version.
Once you have selected a version, click the options button (three dots) in the top right and select the Download Version option.
You will then see an options to choose the format, and select whether to include the notebook description and header along with any comments added to the notebook.
For more information, see: Notebook Versioning