Bond, Helen J., author
Blackstone, 1990
Buku Teks
Bays, Alfred W., author
Macmillan, 1931
Buku Teks
Barnes, A. James, author
Mc-Graw Hill, 2009
Buku Teks
Marsh, S.B., author
MCGraw-Hill, 1995
Buku Teks
Clark, Lawrence S., author
McGraw-Hill, 1988.
Buku Teks