Rehm, M., Notten, A., Glott, R., Hagemann, P., Seibold, B., Bijlsma, L., u. a..  (2013).  Open Education Case Studies ? A Variety of Shades and Formats. In Openness and Education (Bd. 1-1, Bd. 1). Bingley, United Kingdom: Emerald Group Publishing Limited.