Black, C.E.
Alfred A. Knopf, 1966
Buku Teks
Black, C.E.
Alfred A. Knopf, 1961
Buku Teks
Schaller, Michael
Oxford University press, 1979
Buku Teks
Keylor, William R., 1944-
Oxford University Press, 1996
Buku Teks
Teed, Peter
Oxford University Press , 1992
Buku Referensi