APA
Beyerlin Ulrich,, . (2011). International environmental law. London: Hart Publishing Company.
Chicago
Beyerlin Ulrich,, . 2011. International environmental law. London: Hart Publishing Company.
Harvard
Beyerlin Ulrich,, . (2011). International environmental law. London: Hart Publishing Company.
MLA
Beyerlin Ulrich,, . International environmental law. London: Hart Publishing Company. 2011.