1. Gaiser, T & Schreiner, A 2009, A guide to conducting online research, Sage: London.
2. Waldorf World List 2019, Directory of Waldorf and Rudolf Steiner Schools, Kindergartens and Teacher Training Centers worldwide, Bund der Freien Waldorfschulen/Hague Circle/IASWECE/Freunde der Erziehungskunst Rudolf Steiner.