It is for my master thesis. Is there any way to customize existing citation styles?


Here is an excerpt from the official guideline:

We recommend that you include short references in a footnote according to the following scheme: Cf. author(s) (year), citation location.
Example: Cf. Schewe (1994), p. 1012 ff. or: Cf. Schewe (1994a), p. 1012 ff.

(...)

- If several publications with the same year of publication are used by one author, the sources are distinguished by the letters a, b, etc. after the year. (cf. example above)
- If several pages of a source are referred to, the first page is listed, followed by "f." for another page or "ff." for several following pages.
- If more than one source is referenced to a statement, only one footnote is made. In other words: Several sources can be mentioned in one footnote. (Multiple sources are separated by semicolons).
- If the number of authors exceeds the number of three, only the first author is written out and the suffix "et al. is added. (et al. is Latin and the abbreviation for "et alii" (masculine), "et aliae" (feminine) or "et alia" (neuter and corresponds to the German abbreviation "u. a." ("and others")). For example, if a source was written by the authors Maier, Müller, Schulze and Kunze in 2014, it is cited as "Maier et al. (2014)".

You should find something like that using this tool: https://editor.citationstyles.org/searchByExample/

(don't put the "p. 3" into that tool as it cannot search for that.