What to cite?
All scholarly arguments that are not based on your own material, your own reasoning and your own opinions must be referenced in the text and cited in the list of references. For example, you must give references to other people’s opinions and assessments, numerical data, models, results and conclusions. Remember that this rule also applies to illustrations/diagrams, tables, sound recordings and images, and that the use of such material has copyright implications.
Matters of common knowledge do not need to be referenced. For example:
On 17 May 1814 all the representatives present at Eidsvoll signed a new constitution for the independent state of Norway and elected Christian Frederik as king.
If you are describing something that is not common knowledge, however, you must declare where you found the information.
It can be difficult to determine what counts as common knowledge. You do not need to reference uncontroversial statements about matters that are within the general knowledge of others working within your field. If you are uncertain, ask your supervisor for advice. Then you avoid suspisions of plagiarism.
Your own lecture notes do not count as sources, and should not be referred to in a thesis. You are obviously free to use them as inspiration while writing, but you have to work with the material, rewrite it and internalise it.
If a lecturer has published lecture notes or handouts electronically you can cite these and refer to the web page where you found them. Read carefully, has the lecturer provided sources?