Do I have to cite myself? If yes, how?

If you are citing yourself, this is called self-citation, and it is treated like any other citation. Although this issue is more commonly addressed by researchers, the following rules apply:

• You should cite yourself whenever you draw from your previous works (e.g., when you use results from research you have already published elsewhere).
• You should follow the same procedure if you are building on your bachelor’s thesis in your master’s thesis. In this case, you must also cite your bachelor’s (or even seminar) work.

When Not to Cite Yourself

• If the results have not been published anywhere (e.g., the results of your survey were not presented in a seminar paper or a conference paper),
• When you are translating and using a foreign language text (article, book, website) in your work and your name does not appear as the translator, it is advisable to add a note, such as “translation by the author” or “translated by the author”.

Guidance on how to cite your own sources according to the APA 7 citation style can be found in the Self-Citation section here.