Princeton University Press , 1950
Buku Teks
Fuson, Robert H.
Kendall/Hunt Publishing Co., 1977
Buku Teks
Taylor Peter J.
Longman, 1993
Buku Teks
edited by Robert Stimson and Kingsley E. Haynes
Edward Elgar, 2012
Buku Teks
Saunders College Publishing, 2000
Buku Teks