1. Ablewicz K. (2010). Hermeneutyka i fenomenologia a pedagogika In: S. Palka (Ed.), Podstawy metodologii badań w pedagogice. Gdańsk: Gdańskie Wydawnictwo Psychologiczne.
2. Böhner G. & Wänke M. (2004). Postawy i zmiana postaw. Gdańsk: Gdańskie Wydawnictwo Psychologiczne.
3. Charmaz K. (2014). Constructing Grounded Theory. 2nd. ed. Los Angeles – London – New Delhi – Singapore – Washington DC: Sage.
4. Act of 14 December 2016 on Educational Law and the Regulation of the Ministry of National Education of February 14, 2017 (Journal of Laws 2018, item 996).
5. Council of Europe (2000). Recommendation 1437 (2000). Non-formal Education. Assembly debate on 24 January 2000 (1st Sitting) (see Doc. 8595, report of the Committee on Culture and Education, rapporteur: Mr Dumitrescu). Text adopted by the Assembly on 24 January 2000 (1st Sitting).