Writing references

Fotograf Erik Cronberg

Citations indicate that you have used external sources in your text. Reference styles contain rules on how to format the citations. You should always use the style recommended by your supervisor or teacher. Sometimes you have a free choice, and it is then important that you are consistent in the style you have decided to use. KI have produced reference guides for APA and Vancouver, the two styles used by most programs at KI. These guides can help you format the citations correctly.

Why use citations?

The most important reasons why you use citations in an academic text are that:

  • the reader has to be able to refer back to the original source and read more
  • the work of the original author receives acknowledgement
  • what you have gathered from a text is clearly differentiated from your own work
  • you demonstrate that you are familiar with your field and this gives the text credibility
  • you need to support or criticize claims
  • you need to compare or illustrate your ideas or results.

Reproducing something verbatim and not crediting the source is cheating and can lead to negative consequences. Some examples of what is regarded as cheating by KI's Disciplinary Committee are:

  • copying text from the internet or other sources without citing the source
  • cooperating with another student without permission (e.g. two students answers are identical, despite the assignment being individual)
  • copying another student's essay or other written piece of work.

Citation, quotation, paraphrasing …

  • A citation is a reference to a published or unpublished source. A citation is used to show that you have used someone else's material to build up your own understanding of the subject.
  • A quotation is an exact reproduction of someone else's statement. A quotation is indicated using quotation marks "…".
  • Paraphrasing is reproducing someone else's text or part of their text using your own words.

Citations in the text

In your text, it is important that you show from where you have taken information that originate from other sources. The rules of the reference styles govern the format of the citations in the text. However, you also need to integrate the citations in your own text and put them in context. In The Academic Phrasebank (produced by the University of Manchester), you find useful examples.


APA (American Psychological Association) is a reference style commonly used in psychology and health sciences. KIB's reference guide to APA is intended primarily for students at Karolinska Institutet. References are to be considered as recommendations based on APA 6.

KIB's reference guide for APA

References in the text include the authors' surnames and dates. You can use author and date in parentheses or mention the author or authors in the sentence and add only the date in parentheses.

... Rodriguez (2014).
Rodriguez (2014) shows that ...

In the text, APA citations have the same format regardless of the type of source. A citation that refers to a book, article or report will contain the same information, author(s) and date. References with different numbers of authors will on the other hand differ a little bit from each other. Read more about how to handle special situations, for example more than one reference in the same parentheses and more than one reference by the same author with the same date. On this page you will also find instructions on how to insert page number(s) in the citation. This is mandatory if you use quotations.

In the reference list you should include author, title and other information that makes it possible to find and identify the reference. The references in the reference list will look different for different kinds of sources. You will find templates and examples in the reference guide.

The reference list is sorted alfabetically after the first author, editor or other entry term. Read more about how to sort the references in the reference list.

The complete manual for the APA style is only available in print, but you will find answers for many questions here:


Vancouver is a reference style established by the International Committee of Medical Journal Editors. It is commonly used in the field of medicine. KIB's reference guide to Vancouver is intended primarily for students at Karolinska Institutet. References are to be considered as recommendations based on International Committee of Medical Journal Editors (ICMJE)s Sample References and Citing Medicine, an e-book on the Vancouver Style by National Library of Medicine.

In the reference list you should include author, title and other information that makes it possible to find and identify the references. You will find templates and examples for different kinds of sources in the reference guide (now available in English!).

KIB's reference guide for Vancouver

In the text you should use numbers in parentheses. More information and examples are found below.

One citation

The citation is listed with numbers in the text.
The citations are numbered sequentially.
The reference list is numbered and is arranged in the order the citations appear in the text.
The numbers are enclosed in parentheses.
Square brackets and superscript numbers can also appear in the Vancouver style.
Only one author is written out in the text, followed by et al.
Example: In Sweden, about 30,000 cases of lung cancer are diagnosed annually (1). Between 1986 and 2005, the number of cases among women has increased by about 3% per year, while the increase among men has stopped (2). The differences between the sexes is connected to the differences in smoking habits in men and women, respectively. Because it takes a long time for lung cancer to develop, these changes reflect smoking habits of many years ago. Smith et al. have indicated a delay of an average of 30 years (3).

More than one citation

Each source appears in the reference list only once, and when a source is cited more than once, the same number is used as when the source was cited for the first time.
If more than one source it cited at the same time, they are separated by a comma and a space.
If more than two sequential sources are cited, they are written with a hyphen in-between them.
Example: Among non-smokers, lung cancer is significantly more common among women than men. Fifteen per cent of all women who get lung cancer have never smoked, while five per cent of men who suffer from lung cancer are non-smokers (1, 3). It is still not clear why this is. Several studies have investigated women's exposure to known risk factors for lung cancer, such as radon (4, 5) and passive smoking (4, 6-8), but no statistically significant link has been found. Studies investigating the link between hormone replacement therapy and lung cancer have arrived at contradictory conclusions (5-7).

Placement of citations

Citations are placed next to the statement they refer to and before the full stop when they are placed at the end of the sentence.
If superscript numbers are used, these are placed after the full stop when the citation is at the end of the sentence.
Example: Lung cancer is more common among female smokers than among male smokers (1), and a possible cause of this is a greater sensitivity to the carcinogenic effect of cigarette smoke among women. Several studies come to the conclusion that women have a greater sensitivity (9–11), while Bain et al., in a large cohort study, could not demonstrate any difference in sensitivity between the sexes (12).

More than one statement with the same source

If an entire paragraph or more than one statement have the same source, this can be shown in the text and the citation only needs to be included once.
Example: Studies indicate that lung cancer may grow more slowly in women. Lindell et al. (13) showed that 85% of the lung tumours that took the more than 400 days to double in volume were found in women. This result is a reflection of the higher incidence among women of forms of cancer with a slower disease progression such as alveolar cell carcinoma and adenocarcinoma, but Lindell et al. found that the time it took for the volume to double was greater in women, regardless of the histological type of lung cancer. Their study also showed that …


If you use quotations in your text, you should give information about page number(s). Include the page number(s) after the reference in the same parentheses . Use the abbreviation p./pp. for page number(s).
Example: "Evidence based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. (1, p. 71)

Citing images

There is no exact standard for how the source of images with unrestricted licences are to be stated, aside from always providing the name of the copyright holder. If you would like to use material with a Creative Commons licence, it is recommended that your acknowledgement includes:

  • name and link to the image,
  • name of the copyright holder and link to their user name, and
  • licence and link to the licence.

Example of how a citation might look for a Creative Commons image.

The copyright holder may often give permission for the image to be used and distributed to a certain extent, for example in a non-commercial context. If you have been permitted to use an image in a certain context, as a rule you must state it's source. There is no exact standard for how the source is to be stated; according to the Swedish Copyright Act (1960:729), "the copyright holder must be stated to the extent required by good practice." What is considered good practice depends on how and when the image will be used. It is best to look at how the copyright holder is usually identified in similar contexts.

Bonus Copyright Access - exceptions for students and teachers

The Higher Education Institutions Agreement allows students and teachers to copy and share copyright-protected material digitally and analogously for example, by:

  • downloading
  • printing
  • inserting into digital presentations
  • saving copied copyrighted material digitally, for example on the university's closed network, on a USB-stick etcetera
  • sharing material on the university's closed network, via e-mail etcetera
  • projecting and displaying on screen
  • handing out paper copies. 

Citing images in the APA and Vancouver Style

You find examples on how to refer to different types of images in the reference guides for APA and Vancouver (choose Ljud & bild). There are more examples on APA references in the APA Blog. A comprehensive collection of examples is found on the website of the Auckland University of Technology, New Zealand.

Citing documents from the web

There are examples for different kinds of sources on the web in the reference guides for APA and Vancouver. Please note that other kinds of sources than those under the heading Webb might be relevant, for example reports (Rapporter) and legislation and other kinds of governmental publications (Offentligt tryck). Choosing the right type of source and deciding what information to include in the reference can be difficult. You are welcome to ask for advice and to discuss possible solutions in KIB-labb.


Before submitting your assignment you should always check the references, both how you have used them in the text and how you have formatted them in the reference list. This checklist might be helpful. Please note that you need to use the guide for APA and Vancouver for detailed information about the format of the references.

Finding citations tricky? Ask us in KIB-labb what the citations should look like!

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