Morgan, Carl
Cheltenham, Ont., Boston Mills Press, 1977
Buku Teks
Clarke, Irwin & Company Limited, 1959
Buku Teks
Masters, Donald C.
D. Van Nostrand, 1958
Buku Teks
Creighton, Donald
Macmillan, 1977
Buku Teks
McInnis, Edgar
Clarke Irwin, 1956
Buku Teks