edited by Ernest B. Harper and Arthur Dunham
Associate Press, 1963
Buku Teks SO
Beneficial Management Institute, [Date of publication not identified]
Buku Teks
Hope, Alec Derwent, 1907-2000
Angus and Robertson, 1974
Buku Teks SO
Hall, Livingston
West Publishing, 1965
Buku Teks SO
Fraser, John
Cambridge University Press, 1984
Buku Teks SO