Accurate citations and precise references are indispensable in scientific work to make the information presented verifiable for factual correctness.
Although there is a standard in Germany (DIN 1505), different practices and conventions have become established in the individual scientific disciplines, which also differ internationally.
To be on the safe side, clarify the desired or required citation system in advance with your lecturers or supervisors. In addition, it is recommended to inform yourself about the specific conventions of your discipline. For many scientific fields there are specialized introductions on scientific working.
More important than the convention used, however, is the correctness of the quotation and the consistent use of a citation method once chosen ("uniformity").
For the purpose of a first overview, only some basic terms and rules can be explained here.
Quotations serve to justify, solidify or illustrate your own statements or working hypotheses. They may be in verbatim (literal, direct) or in paraphrased (reformulated, indirect) form.
If they are verbatim, they must be marked with quotation marks (by default) and must always follow the original exactly in wording and punctuation. Deviations from the original must be marked as such. Verbatim quotations that are longer than three lines are usually indented and written with a single line spacing.
The beginning and end of paraphrases must be made clear by linguistic means.
In order not to become intellectual theft ("plagiarism"), quotations must be clearly marked by precise citations.
Note: The direct or redesigned transfer of non-linguistic information (pictures, graphics, etc.) is also considered as a quotation and must be marked as such!
- Text: full or short citations
A citation must be sufficiently precise to enable the source to be identified by the information provided. Its form differs not only according to subject-specific conventions, but also according to where it is inserted in one's own work.
It can be placed as follows, depending on the chosen citation system:
* as full citation in a footnote (example)
* as short citation in a footnote (example)
* as short citation in the text (example)
In most disciplines the choice of short citations is common practice today. Short citations do not give the complete bibliographic details of the cited texts, but refer to the corresponding entries in the list of references. They save work when writing and make the reading of a scientific paper easier.
The form and design of short citations can vary greatly depending on the citation rules selected. Some regulations, for example, demand short citations in the form 'author-year-short title-(location)', such as "Jele (2003): Scientific working, p. 11". Such citations help the reader to better classify the cited work without having to look up the list of references. However, they are quite long and therefore only suitable for footnote variants.
On the opposite side are sets of rules in which citation numbers are used: The citation used here is a number that uniquely refers to an entry in a numbered list of references - a variant that requires little space, is suitable for in-text citations and is often found in the natural sciences.
- List of references: references
Lists of references are generally obligatory for term papers or theses. They are also useful for all other scientific documents to provide a quick overview of the literature used. The form of the information in the list of references is influenced by the type of citations in the text.
A list of references lists all - and only all - document sources that have been cited in one's own work.
Depending on the subject, the order of the entries in the list of references can look different. In law, for example, list of references are often divided into "sources" (legal texts, historical documents, original texts by writers, etc.) and "literature" (secondary literature). In many other disciplines, all document sources are listed alphabetically without further distinction.
Which bibliographic information is included in an entry and in what way depends on the type of work cited (e.g. printed book, printed journal article, e-book, etc.) and on the citation rules chosen. Typical bibliographic data in the case of printed books are:
* author / editor
* year of publication
* edition (will be called from 2nd edition on)
* place of publishing
Example: Birnbacher, Dieter (2013): Analytical Introduction to Ethics, 3rd ed., Berlin: de Gruyter.
Usual bibliographical data in the case of printed journal articles are:
* author of the article
* year of publication
* title of the article
* title of the journal
* volume of the journal
* issue number
* page numbers of the article in the journal
Example: Perini, Laura (2005): The truth in pictures. Philosophy of Science, 72(1), pp. 262-285.
- Add-on: citing from electronic resources
As with printed works, the precise location of the quotation must be indicated for electronic sources. Each quotation must therefore be marked with the exact address. It is not sufficient to specify only the initial page (homepage) when quoting from subsequent pages.
If possible, a standardised and long-term secured address, a so-called persistent identifier, e.g. an URN or a DOI, should be used as the internet address of the document.
The date of the last revision as well as possible information on the version of the document provide information on the status of the document. If neither of these can be found in the document, the date of your own download should be mentioned in the reference. (Note: In the case of a DOI, it is not necessary to specify a last retrieval date).
Example: Earman, John / Wüthrich, Christian (2016): Time machines. In: Edward Zalta (ed.): The Stanford Encyclopedia of Philosophy, Stanford University: Center for the Study of Language and Information, URL: plato.stanford.edu/entries/time-machine/ (last visited: 10 Aug 2018 ).