You should note that references or citations are distinct from bibliographies. The key thing to remember about references and citations is that they are used to acknowledge the source of information that you have borrowed from someone else. You must always have a reference after direct quotes, statistics and ideas that you are using in your essay. In addition, you can use references and citations to substantiate claims that you make. Note however that it is counter-productive to have a long bibliography and then have references to only two of the works cited there.
Examiners can easily spot 'padded' bibliographies.
At this advanced level, examiners will usually expect to see use of the specialist literature and a balance of primary and secondary sources where appropriate. In your bibliography at the end of your essay you must list all the books and articles, audio-visual, internet or other material that you have used to write the essay. Remember to take down all these details when taking your notes. Author, 'Title of article' Name of Journal or Name of Journal volume, number, date, pages. Creating International History' Diplomacy and Statecraft vol.