Punctuation that appears in your formatted references can be changed by editing the style you are using. When you edit a style, you can delete unwanted punctuation, replace it with other punctuation, or add additional punctuation where necessary.
For example, if the Numbered style creates a perfect bibliography for your document except that it puts a comma after the authors’ names where you need a period, you can edit the Numbered style to make this change.
To edit the Numbered style:
Select the Numbered style from the Output Styles menu.
Select Edit Numbered from the Output Styles menu to open the Numbered Style window.
Click the Templates option under the Bibliography heading.
For each reference type (such as Generic, Journal Article, and Book), delete the comma that follows the field name "Author" and type a period.
The style’s bibliographic templates should now look like the example below. Notice that the punctuation after the Author field in each template has been changed to a period.
From the File menu, select Save As. In the dialog that appears, enter a new name for this modified Numbered style, and then click Save.
Now you can use the new style to create a formatted bibliography that puts a period between the author names and the titles.
For information about making punctuation or spaces appear only under certain circumstances see Special Formatting Characters. That topic also explains the use of the non-breaking spaces (◊), vertical bars (|), accent grave (`), and the carets (^) that you see in the style templates.
Note: If you save a new style into a folder other than the current styles folder, it will not be available in the Style Manager. You should save new styles to your Styles folder, or change Folder Locations Preferences if necessary.