How to use multi theme

I now use jane theme. It’s very good.
Now I want to add new type to use new theme.
show some page is jane theme, some page is book theme.

I read hugo docs:

Who can support hugo example project.

I found:
Will content/* have sub folders for blog and tutorials? If so, these sub folders would be sections. In your layouts folder you replicate these sub folders / sections with the templates you want for each section.

If not (if everything just files inside the content folder), the use add ‘type’ to the front matter to define sections manualy. In layouts folder do the same as above, with the sub folder matching the name given to ‘type’.

this docs is also good

You can manually merge two themes into each other, or load them as components if they are created in a way that work, but there is no guarantee, and this is not a common use-case as far as most users’ understanding of “theme”.

But theme components aren’t the answer to combining arbitrary complete site themes together. You’ll need to work on it manually.