There are various styles to accommodate the needs of different disciplines. For example the Chicago notes & bibliography style is useful for sources where the author is not known which might be the case for older literary or philosophical works.
Your professor usually decides on which style you should use, so follow their instructions. If no style has been indicated then keep in mind that each discipline will have a preferred style. Here are some examples:
- APA: Social sciences, Education and Business
- Chicago: International Studies, Philosophy and History
- MLA: Literature, Religion and Communications