Waldau, Paul: Animal Studies. An Introduction. Oxford ; New York 2013. Internet: https://books.google.de/books?id=YXPn8hvXZd4C&printsec=frontcover&dq=Animal+Studies+an+Introduction&hl=en&sa=X&redir_esc=y#v=onepage&q=Animal%20Studies%20an%20Introduction&f=false.