Goodwin, Grenville, author
University of Chicago Press, 1942
Buku Teks
Eggan, Fred
The University of Chicago Press, 1950
Buku Teks
Dreitzel, Hans Peter
MacMillan Press , 1971
Buku Teks
Burke, W. Warner, author
University Associates, 1972
Buku Teks
edited by Paul Bohannan and John Middleton
Natural History Press, 1968
Buku Teks