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.
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In the notebook details view, click the Versions button in the top right and select the relevant version.
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Once you have selected a version, click the options button (three dots) in the top right and select the Download Version option.
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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.
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For more information, see: Notebook Versioning