What to include
A bibliography is the list of sources used by the researcher in carrying out a piece of research. It does not only include any written works quoted or referenced, but also other materials, eg any pieces of music, visual records, or films. If non-written sources constitute a substantial part of your research project, then they ought be listed separately: in a filmography if your thesis is concerned with film, or a section crediting the visual material mentioned if your investigation had an art-historical/theoretical focus. Anything that has offered a significant contribution to the development of your research must be represented within the bibliography.
The different stages of working with your bibliography
Bibliographies figure at the end of any academic piece of writing, but they are obviously crucial to your research process from the moment you set out to investigate a new issue. One way of finding out about the seminal works in your field is to consult the bibliographies of the most recent publications relating to your topic; in the case of Romance studies not only in English but also in the language in which your research is rooted. The initial work with a general bibliography will give you a sense of what research has already been done and the work that is left to do. Keep annotating your bibliography. It is terribly useful to keep notes on your reading - you may think you will remember, but after three years of PhD research you will appreciate any descriptive or evaluative comments noted down on your work-in-progress bibliography. As you read and write you will add to and refine your bibliography until finally it becomes the bibliography situated at the end of your thesis.
The final bibliography of your PhD or Masters thesis will reflect not only the works you explicitly refer to in your research, but any sources that you may have consulted, looked at and read during the exploration of your topic. The fact that you decided not to cite from these works is not decisive.
Consistency: decide for a style system early on and stick to it
When you first start building up your bibliography for a PhD dissertation, you may feel very far away from the final writing-up stages before submission. In this last phase you will be overwhelmed with the task of polishing and concluding an extensive piece of writing, a text longer than anything you are likely to have produced before. You will do yourself a great favour if you decide on a particular reference style when you start setting up your bibliography and carry it through whilst updating this list throughout the whole period of your research. This is one huge task taken off your shoulders when you come to the last stretches of finishing off. Many British universities adopt the same system for Arts research, the MHRA system (to view our pages on the MHRA system), but whatever you opt for, you must be consistent. If for example the system that your university requires prescribes a comma after the name of the author, you cannot just alternate the comma with a semicolon. When starting your research, inform yourself whether your university requires a particular reference system, so that you won't waste any time on standardizing your bibliographical entries at the end of your research.
Be meticulous about noting down your bibliographical references
Another quite common mistake is failing to copy down the complete bibliographical references on the first occasion, thinking that you will always have the opportunity to perfect them at a later stage if this was to prove really necessary. You will regret this later. In some cases you may not have those documents at your disposal again, and even if you have, you are wasting a great amount of time.
Avoid trying to read everything
When following up on all the different publications you have collated in your general work-in-progress bibliography, you may easily be tempted by the desire to read everything, however marginal. Such an attitude is not only extremely dangerous, since you are expected to complete your research in three years, but also unprofessional. Part of becoming an academic is to learn how to work towards deadlines and produce research within given limitations of time. No one can have proper firsthand knowledge of every single essay that has been written in a particular discipline. Academic research is about specialization and not about general knowledge, so keep weighing up what is really relevant to your dissertation. If however you are working in an area where not much has been written, eg you are dealing with a living writer or some very obscure works of earlier periods then you will be expected to have read everything on your subject.
Exclude dictionaries and encyclopedias
Normally a bibliography does not record dictionaries and encyclopedias, unless they have been consulted in certain ways: for example, you may have referred to an entry in an eighteenth-century encyclopedia, or you want to substantiate or juxtapose some very specific definitions laid out in dictionaries.