Cole, George Douglas Howard, 1889-1959
Routledge and Paul, 1955
Buku Teks
G.D.H.Cole
Carter lane, 1955
Buku Teks
Forcese, Dennis P.
McGraw-Hill Ryerson, 1980
Buku Teks
Abercrombie, Nicholas
Basil Blackwell, 1980
Buku Teks
Womack, James G.
Benziger Bros, 1966
Buku Teks