Schwalm, H. (2010). Outdoor and outside: Die Outsiderszene im Ruhrgebiet. Kettler.
Citazione stile Chigago Style (17a edizione)Schwalm, Hans-Jürgen. Outdoor and Outside: Die Outsiderszene Im Ruhrgebiet. Bönen: Kettler, 2010.
Citatione MLA (8a ed.)Schwalm, Hans-Jürgen. Outdoor and Outside: Die Outsiderszene Im Ruhrgebiet. Kettler, 2010.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.