APA
Birks Peter,, . (2006). The classification of obligations. Oxford: Clarendon Press.
Chicago
Birks Peter,, . 2006. The classification of obligations. Oxford: Clarendon Press.
Harvard
Birks Peter,, . (2006). The classification of obligations. Oxford: Clarendon Press.
MLA
Birks Peter,, . The classification of obligations. Oxford: Clarendon Press. 2006.