Cole, George Douglas Howard, 1889-1959
Routledge and Kegan Paul, 1955
Buku Teks
Cole, George Douglas Howard, 1889-1959
Routledge and Paul, 1955
Buku Teks SO
Forcese, Dennis P.
McGraw-Hill Ryerson, 1980
Buku Teks SO
Abercrombie, Nicholas
Basil Blackwell, 1980
Buku Teks SO
Mills, Edwin S.
Johns Hopkins Press, 1972
Buku Teks SO