page break from two column to one in master document

I’m writing a book consisting of three parts: preface, main body and references.
I am able to do the first two parts but unable to do the third part: how do I change from two columns in the main body to one column for references (third part) where I need to insert five tabulations (hence I need one column).
In page style, I created ‘references’ but when I set to one column, all the previous pages (main body) changed to one column.

Page styles are applied to bounded parts of a document. Setting a page style acts on the current part.

If your whole document changes, this means you have not defined correctly the “boundaries”.

A “boundary” is a special page break which can be created in two ways:

  • in a paragraph style, Text Flow tab
  • with Insert>Break>More breaks

In both cases, you must explicitly select the page style to switch to after the break. If you don’t do that, no boundary is created and you aren’t able to page-format differently the flows before and after the break.

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