Griffin, Sean, author
Wiley Blackwell, 2018
Buku Teks
Musser, Charles, author
Macmillan Library reference USA,, 1990
Buku Referensi
Koszarski, Richard, author
Macmillan Library Reference USA,, 1990
Buku Referensi
Simpson, David, author
Oxford University Press , 1986
Buku Teks
Gagey, Edmond M., author
Columbia University Press, 1948
Buku Teks