APA
Bekoff M., . (1998). Animal play. Cambridge: Cambridge Univeristy Press.
Chicago
Bekoff Marc, . 1998. Animal play. Cambridge: Cambridge Univeristy Press.
Harvard
Bekoff M., . (1998). Animal play. Cambridge: Cambridge Univeristy Press.
MLA
Bekoff Marc, . Animal play. Cambridge: Cambridge Univeristy Press. 1998.