Using citations and references to show the origin of presented information is an important part of academic writing. It serves several purposes such as adding credibility to the text and avoiding plagiarism.

There are many different systems for referencing. They all have in common that sources should be presented with information such as author, title, year, etc, that help the reader assess the the source's credibility without searching for it. Different universities, departments, and/or research groups may use different systems. If you are unsure of which system to use, ask your supervisor or responsible teacher.

• Uppsala University Library's Citation Guide.
• A good overview of reference management in general can be found here. The Harvard and Vancouver systems are also discussed.
• Some common referencing styles with many examples of different sources can be found here.