APA-viite (7. p.)

Friedrich. (2013). International Environmental “soft law” (1.). Springer Berlin Heidelberg.

Chicago-viite (17. p.)

Friedrich. International Environmental €œsoft Law”. 1. Springer Berlin Heidelberg, 2013.

MLA-viite (8. p.)

Friedrich. International Environmental €œsoft Law”. 1. Springer Berlin Heidelberg, 2013.