edited by Joseph Seibert & Gorden [i.e. Gordon] Wills
Penguin Books, 1970
Buku Referensi
Holmes, Parker M.
South-Western Publishing Co., 1960
Buku Teks
Clark, Fred E., author
Macmillan, 1931
Buku Teks
McNair, Malcolm P., author
McGraw-Hill, 1949
Buku Teks
Westing, John Howard, author
Prentice-Hall, 1957
Buku Teks