Make your thesis work plan and project plan carefully. These help you to understand what you are going to do and what kind of sources you are going to need in your thesis.
See the Savonia instructions for your thesis in Reppu.
Be careful when citing theses since their quality can vary. However, theses can be useful in providing an example of what kind of research has been done on your subject. Also, bibliographies provide useful tips on other relevant research. Thus, theses can be a good starting point for your search.
You can find most of the theses of Universities of Applied Sciences on the Internet via Theseus. It's possible to limit your search for example to Savonia. Our theses are also in Savonia-Finna.
You can search for the theses of Finnish universities in Finna.fi (choose content type after your search). However, not all of them are catalogued to the database. You can also use the library catalogues of certain universities to find theses.