Isenberg, Andrew C.: The destruction of the bison: an environmental history, 1750-1920. Cambridge; New York 2010. Internet: https://books.google.de/books?id=s_lyumM8d84C&printsec=frontcover&dq=The+Destruction+of+the+Bison.+An+Environmental+History,+1750%E2%80%931920&hl=en&sa=X&ved=0ahUKEwiplv63prDTAhXG5xoKHVMkACgQ6AEIJDAA#v=onepage&q&f=false.