In your scientific work, you will have to include many quotes, because everything that does not come from you as the author, must be identified. In addition, any scientific work will need to rely on existing facts or studies to derive or substantiate its own hypotheses. The sources from which you quoted in your work, you must specify in the bibliography. There are certain guidelines for both citation and citation (which may vary from lecturer to lecturer or from chair to chair). Basically, however, certain standards apply.
Direct and indirect
In the case of citations, it is first necessary to distinguish between literal and direct and analogous or indirect quotations. Important is: the correct source must be present in both forms! Shorter direct quotes must always be in quotation marks. In doing so, the introductory one below and the finishing one must stand up. For indirect quotations you do not need quotation marks and always use cs. (compare). If the direct quote exceeds a length of about three to four lines, it must be deducted from the rest of the text. In this case, you enter it from the left edge, reduce the font size minimally and insert a one-line distance. This labeling then makes the quotation marks superfluous.
If quoted in the quotation, you must mark this with single quotation marks. If you leave something that originally occurs in the source, you indicate this with square brackets and three dots: […]. If there is a spelling mistake in the quote (except old spelling), you do not improve it, but mark it with square brackets and “sic”: [sic]. Own additions to the quote you have to with square brackets and possibly “d. Verf. “(The author) states: [supplement, d. Ed.].
When referring to another source in a source that you use for your work, it is called secondary literature. You should try to locate the original work in order to preserve scientific accuracy. It could also be that the author of your source has already cited wrongly and you would then, just as wrong, take over. That’s why you’re always on the safe side if you get the source and quote directly from it. So you can then include them in your own bibliography after a good conscience.
American citation or Harvard system
In the American citation you put the source in parentheses just behind the quote in the body text. Here you name the surname of the author, the year of publication of the cited work and the page number to which you refer.
Example: “Pathological research has focused all our attention exclusively on the repressed.” (Freud 1923, p. 5)
German citation or footnote system
If you choose the footnote system, you place a small number at the end of the quote, which is then executed at the bottom of the page. Given here are the first and last name of the author, short title and year of publication of the source and page number.
Example: “Pathological research has focused all our attention exclusively on the repressed.”
Footnote: Freud, Sigmund: The I and the Es (1923), p. 5
If you quote from exactly the same source in the next footnote, it suffices to write ibid. (Ibid.).
Structure of the footnotes
The footnotes at the foot of the page have a text size of only 10 pt and also a smaller line spacing (1.0) than the continuous text (1.5) in order to distinguish them from them. Footnotes may also be used for additional comments. However, you have to be very careful here, because everything relevant to your scientific work must appear in the body text. In addition, the footnotes should under no circumstances become too extensive.
Which citation is the better?
If there are no instructions from your lecturer, you can freely choose one of the two citation methods. The American, however, is the somewhat confusing, since the text, depending on the amount of citations, often for the relatively long source references must be interrupted. The German citation method is more elaborate and will certainly cost you a little more time. Here is a little tip: put the footnotes in any case during your writing process, so right after you have set the quote. The assignment, after you have already completed your work, is very confusing and takes an unnecessary amount of time (and nerves).