New worlds, new animals: from menagerie to zoological park in the nineteenth century. Hrsg. v. R. J. Hoage/ William A. Deiss/ National Zoological Park (U.S.). Baltimore 1996. Internet: https://books.google.de/books?id=15AsyQ8O2qoC&printsec=frontcover&dq=Hoage,+Robert/Deiss,+William+A.:+New+Worlds,+New+Animals.+From+Menagerie+to+Zoological+Park+in+the+19th+Century.&hl=en&sa=X&ved=0ahUKEwi6xsTLobbVAhVLvxQKHQ8eDJoQ6AEIJjAA#v=onepage&q&f=false.