Each time you use information from another source you should write an in-text reference. The in-text reference can consist of a parenthesis which contains the author’s last name and publication year, and possibly also page number, but it can also consist of only a number (notes). In both cases it should refer to the complete reference in the reference list. For word-for-word quotes you should always give a page reference. When you paraphrase, you should give a page reference if you refer to a certain page or certain pages in a work, but not however if the paraphrase concerns the whole work.
All sources that you quote or paraphrase must be included in a reference list, also called bibliography. This list should contain all the information about the different sources which is needed for them to be distinguished from other sources, and for them to be retrieved easily.
To find out how you should write your references depends on the citation style. There are a number of different citation styles, but they have one thing in common, namely that they describe exactly which information about the original source you need to give, and what the text reference and the complete reference should look like. Because different disciplines use different citation styles, it is important to use one which is generally accepted in your subject and use it consistently throughout the whole text. Check with your lecturer which style is recommended for your subject.
Here are some commonly used styles:
- APA – mostly used in behavioural and social science
- Harvard – used in several disciplines
- IEEE – used in the field of technology
- MLA – used in literature studies
- Oxford – used in history, law, theology and other fields where many unpublished sources are used
- Vancouver – used mainly in medicine and biomedicine
Guides to these styles and others can be found on the Internet (e.g. see this list) and as books. Ask at your university library.