References will be numbered in the order they are added to a page. If the reference has been previously cited, it will use the number of the previous citation and add a letter (e.g., 3b). If you wish to change the order of references within a page from the current order, e.g., a page with four new references had citations numbers of 4-8, but you wanted number 7 to be number 4 and then the rest to be 5, 6, 7 and 8 in their current order, you would need to change the order of the citations.
To change the Citation order:
- Select the page in question.
- Click on Properties icon or double click on the page.
- From the Page Properties window (in the right flyout) click on the Citations tab.
- The citations for the page will be listed with the order and a short version of the citation. Simply drag and drop to change the citation order. When you drop an item you will see that the order column will be updated with the changed order. When you have made your final changes, click on Update.