Continue this process as you write.  Citations can be added or deleted and Zotero will keep track of them as you go.  Once the document is complete, create a reference section and select Add/Edit Bibliography from the Zotero options in the editor's toolbar.  A reference list will be created for each (Fig. 8)  based on the citation style you selected when setting up Document Preferences.  Libre Writer users will find similar icons to those pictured here.