The types that are displayed depend on the different literature sources.
Type
Lists the available bibliography entries. To add an entry to the Structure line, click the entry, click in an empty box on the Structure line, and then click Insert. Use the Define Bibliography Entry dialog to add new entries.
Insert
Adds the reference code for the selected bibliography entry to the Structure line. Select an entry in the list, click in an empty box, and then click this button.
Remove
Removes the selected reference code from the Structure line.
Sort by
Specify the sorting options for the bibliography entries.
Document position
Sorts the bibliography entries according to the position of their references in the document. Select this option if you want to use automatically numbered references.
Content
Sorts the bibliography entries by the Sort keys that you specify, for example, by author or by year of publication.
Sort keys
1, 2 or 3
Select the entry by which to sort the bibliography entries. This option is only available if you select the Content radio button in the Sort by area.
AZ
Sorts the bibliography entries in ascending alphanumerical order.
ZA
Sorts the bibliography entries in a descending alphanumerical order.