Macmillan, 1967
Buku Teks
Mussey, Henry R.
Ginn and Company, 1947
Buku Teks
Wicksteed, Philip Henry, 1844-1927, author
Augus M. Kelley, 1950
Buku Teks
Stonier, Alfred W.
Longman Group Limited, 1980
Buku Teks
Katz, Bernard S.
Garland Publihing, INC, 1988
Buku Teks