Blank bibliography

I am using libreoffice to write my class literature survey, at the end of my article I need add the bibliography, I try to add three entries in “Tools”->“Bibliography Database”, then “insert”->“indexes and tables”->“indexes and tables”, at the first tag, I changed “type” from “Table of Contents” to “Bibliography”, then click “ok”, my bibliography is just a title “bibliography” and no any entries. I wonder why?

I have figured it out. I did not make any the references in my article, so although there are three entries in my Bibliography Database, I got the empty bibliography list. After I mark all the annotated bibliography, I got the what bibliography i want.

Is it possible to create a bibliography with no document references to it? just from selected entries of the Bibliography Database?